math-help

[undone basin]

why ??

when do u take the reciprocal to the left of the intergral ?

i dont get it

[candid rivet]

do you have an example that you don't understand ? Because it is true that the integral of 5f is 5 times the integral of f (still true if you replace the 5 by any number)

[strange river]

if I am understanding your question correctly, it typically doesn't matter whether or not you take a constant out of an integral. Personally, I take a constant out if it makes the integral visually easier to understand and compute. But regardless, you'll get the same end result because,,, it's constant 😎 lol
as for multiplying an integral by the reciprocal of a constant, the only situation that comes to mind when doing this is u-substitution. Sometimes to make a u-sub work, you'll have to multiply the integral by a constant to get the proper derivative to cancel things out. and in order to keep things equal, you'll have to multiply the entire integral by the reciprocal of the constant. Does this sound familiar?

[frail hearth]

can anyone of you guys teach me compound interest please

[ivory wyvern]

Compound interest is just the idea of a small amount of interest: for example, imagine taking 3% interest per year on a 100 dollar loan, and then imagine the seeing how that progresses over many years. The first year, it would be 103 (100 * 1.03) dollars you owe, then 106.09 (100 * 1.03^2) in 2 years. This seems like a small increment, but in only 20 years you will owe 180 dollars (100 * 1.03^20). The point is, that even a small interest rate will increase in size over time, as each year you increase the amount you owe by multiplying the money you owed last year by the interest rate, not just by paying the initial 3 dollars extra for the first year. So, instead of paying 60 dollars extra for 20 years (100 * 0.03 * 20 = 60), you’d pay 80 extra (100 * 1.03^20 - 100 = 80).

[frail hearth]

i still dont get it ..... sorry 😢

do you mind teaching me with a example?

[solar mesa]

isnt cospi/2 0?

[solar mesa]

why did it open with negative sign

[ashen pine]

I can teach you compound interest over voice call on discord if you are interested. Unfortunately i dont have a drawing pad or smth to do calculations

[ashen pine]

i think the equal to sign should be with the first piecewise definition

[frail hearth]

Thank you, but i just finished my test on it...Ill update you on the results...

[ashen pine]

Sure!

[ivory wyvern]

Here’s the full derivation

[ashen pine]

Can we like do like this that if it has unique eigen values then it will be diagonalisable?

[ivory wyvern]

Yep, we can

If an n×n matrix has n distinct eigenvalues then A is diagonalisable.

[ashen pine]

Cool!

Thanks

[obsidian spire]

y_1 ' = k, y_2 ' = e^x. So you have kx = e^x and k=e^x. Since e^x=e^x, you have kx=k. So what value is x?

Then everything should be solvable

[obsidian spire]

I'm trying to review some problems for real analysis. If someone could check my answer I'd appreciate it.

[simple ferry]

can anyone please help me with this I'm unable to understand

[candid rivet]

Looks good to me !
I just don't think the "< a^2 +1" is needed to conclude that (t_n) is bounded
And also if you have seen the 2 folowing properties:
If the series of a_n converges then a_n ->0 (for n -> +infinity)
If for all n 0<=a_n <= b_n and series of b_n converges, then series of a_n converges
Then you can say that at some point we know that a_n wil be lesser than 1, so 0 <= (a_n)^2 < a_n, and since series of a_n converges it implies that the series of (a_n)^2 converges

[obsidian spire]

I like your way of proving it, it's a lot faster and would be better on a test. Though we need |a_n| to make sure the inequality holds in all cases i think, and since it's absolutely convergent it works perfectly

[candid rivet]

absolutely, my 2nd property needs a_n and b_n to be positive real numbers !

[eternal elk]

Why it's so challenging to understand permutations and combinations

[sacred marsh]

It's simply double derivative.
First Z with P then with T = L with T
Then, Z with T then with P = M with P

[sacred marsh]

What course are you doing to be studying this?

[ashen pine]

I guess thermodynamics

[deep marsh]

Hi I'm studying calculus 1&2 , and this book is really helpful

[simple ferry]

thankyou!!

[simple ferry]

yes

[simple ferry]

thanks for sharing!

[undone temple]

I'm struggling a little bit to study linear systems. Can someone help me with this question?

[ember garnet]

in this case if you add the two equations you'll get an equation with only one unknown variable, x

[barren oasis]

yea just combine the right sides and the left sides and you will get

2x+y + x-y = 200 + 30 so when adding up that makes 3x=230 and you solve for x

[left knoll]

here you can either substitute the value of x from the second equation in the first one and then solve which is a long procedure or you can multiply both the equations with the common factor of either one of the variable and then subtract. by doing so, you are directly cancelling out 1 variable

[obsidian spire]

What everyone said above is correct. You can think of these systems a bit like if someone told you 'all of these equations are true'.

Since they are true, you are allowed to do various things with them, like add multiples of them to each other (since it's similar to adding 30 to both sides which doesn't change the equality of other equations), or make substitutions based on them. And this can allow you to isolate and solve the variables

[undone temple]

Thanks for the help guys. I'm getting confident solving some questions now!

[left knoll]

yaayyy!!

[tawny coral]

I love the organic chemistry tutor for maths, I actually prefer them over his science-related videos

[vital dragon]

bro saved me countless times last year

mine is professor leonard

he stopped uploading but he still has a ton of content

i also started watching 3blue1brown

[obsidian spire]

Professor Leonard on youtube worked well for me, I feel he gives pretty clear explanations

[junior zinc]

how would l do 1b)

[tawny coral]

yeahh I loved their videos with terence tao

[junior zinc]

nvm i got it now, for anyone wondering it was [19.93,19.94]

[nocturne grail]

Does anyone have a YouTube course they recommend for real analysis?

[stuck creek]

Anyone have any recommendations to people trying to learn undergraduate level mathematics after an unrelated first degree?

Any short courses, diplomas or accreditations someone could strive for? Self learning curriculums?

(context! I'm trying to go into computational applied mathematics after my computer science degree and build the skill gap I have)

[weak lotus]

MIT opencourseware

[stuck creek]

thanks I'll give that a look rn!!

[vital shard]

Mathepeter if ur German 🐺

[thick copper]

greetings anyone got tips to get better at maths

Its been 4 months so far did two tests both tests came back to me with same percentage, exactly same percentage. The first one was easier (shorter) while the most recent was longer. Literally, no improvement from the start of my course according to the tests I took.

[stuck creek]

what strategies have you tried so far?

[somber zenith]

if a = c and b = c then a = b and also if a < c and c < b then a < b
math is beautiful!

[slender temple]

can someone help me with this basic physics question?

[thick copper]

I mean I guess my best bet is too have a tutor to help me both in motivation and accountability and to cover more ground on topics. But to answer your question; revision practice questions. But I just generally, am the type of guy that is just not always in the moment. I just find it tough cause I am working with a low maths foundation score and jumping into tough concepts. I did not do terribly. Is just that I am surrounded with really good students. SOS

[stuck creek]

Ahh I get that a whole lot honestly. That was me when I was doing my A-Levels.
I had a lot of foundational gaps because of the lack of drive in my earlier years.

Anyway, the thing that really helped me the most was having a tutor that not only helped with explaining topics one on one, but would sort of have these investigative moments with me.

Like our main goal would be to try and identify what prerequisites were missing, and like, help me understand how the concepts come together. It would give me a bit of a better way forward, and it would sort of make things seem less daunting to work towards since I have a plan and can also work on things on myself rather than only making progress when I'm with my tutor.

Still though, tough and a lot of work, but now having a bit of a clear outline on what IS necessary for me to learn X, and what I'm doing right so far, etc, made math really fun for me. Felt like a videogame where all the objectives were super clear, since sometimes I found in class my Teacher would sort of brush over some things and I really would not have a measure of improvement other than the tricky parts, which really were more like milestones rather than a better representation of my overall progress in maths.

I had moments where I'd make leaps of improvement because some certain things finally clicked etc.

Progress might feel jagged, but as long as you consistently work and identify weaknesses, you'll be growing 🫶🏾

Anyway this is just from what helped me personally.

Sorry if it's a very generic answer, oof, hopefully some other folks share their own tips. I get how tough the climb can feel especially when you don't have too many peers that specifically relate to your scenario.

[left knoll]

need help with this one

[indigo totem]

hah, A level math

that stuff doesnt matter in uni

havent done a single proof in my life 💀

[stuck creek]

I mean it depends on your course lmao

[ivory wyvern]

I think your best bet is to look at the course requirements for undergraduate degrees in applied mathematics/computational Mathematics and then go through the list of courses they have and attempt to study up that point. I would say though, if you graduated with a cs degree you will have to put a decent amount of time in, as you will have to go through a basic differential equations course, a decently comprehensive linear algebra course, multivariable calculus, and then multiple (2-3) applied mathematics courses so you have experience actually coding projects to show proof of your ability to use high level mathematics. I think it’s doable, as long as you are willing to devote a few months to focusing on these subjects

[thick copper]

thanks

[stuck creek]

Gotcha gotcha, thank you for the pointers and thought you put into this response :))

Seems like there's a whole lot to go over and I'm super excited to buckle down and dive into it all!! Gonna graduate in a few months and take a gap year, then dedicate that time to studying maths on my own terms. Then maybe once I know more I could have a bit of a direction to go in.

I have no plans other than to learn lol, and I'm pretty content with that!!
Done a bit of applied mathematics but that's just one module (I do computer science (Games Technologies)), so it feels like this whole other world I'm gonna dive into its all really exciting

I'll probably end up being a lot more active on this server actually lol

TLDR:
YIPPIE

[dark oar]

goodluck!

[stuck creek]

thank you!!

[ivory wyvern]

Good luck!!

[obsidian spire]

Getting better at stuff.. there is a lot that goes into that. Youre gonna want to come up with a way of studying you find fun and make it something very doable. Also something effective at helping you learn new stuff. A lot of times the biggest barrier to getting more studying in is just getting started. If you have a big problem with getting started, just focus on studying for 1 minute and see where it goes from there.

Also you want something that addresses any weaknesses you have. Ideally when you look at a math problem, you want to understand everything you are seeing mentioned there. If theres something you don't get, I'd say investigate it until you understand. Until you can close your eyes and explain what the thing is from memory. Everytime you fix a weakness like that, you grow stronger in math.

[whole copper]

Can someone pls help me , it’s due tmmrw

[ember garnet]

what's the question?

[whole copper]

It was a joke

[indigo totem]

ahh the classic riemann zeta function

my man out here doing a phd version 10

[timid delta]

2+2=4

[dull viper]

6 if you consider another plane

[stuck creek]

0 if you close your eyes

[lavish quartz]

0 = 1
can you prove?

[small siren]

Ah yes, the ol' Riemann zeta function. I solved it last Tuesday while microwaving pizza and petting my cat named Schrödinger.
Spoiler: it was simultaneously solved and not solved.

[whole copper]

It’s not, but 0! == 1 is

[lavish quartz]

no 0 = 1, there is video on youtube. i saw that

[small siren]

0 = 1? let me just rewrite the universe real quick.

[whole copper]

i saw a video that earth was flat , on youtube asw

smh

[indigo totem]

i think i remember seeing that video in particular actually

and the reason why the proof is wrong is he divided by zero when he was factoring out things iirc

[brave loom]

If you are talking about proving 0=1 by exponential method, then let me tell you a fact, that the statement "if base are equal then power are equal" is not valid always

And why is everyone behind 0=1, try 0=2 someday lmaoo

[obsidian spire]

0 x infinity will equal any number you want

[timid delta]

no

tending to 0 x infintiy

not absolute 0

[winged cove]

Hello! I'm struggling to wrap my head around the relationship between angular motion and linear motion.

Anyone got a good resource/textbook to read on the topic? In context of 3D rigid body mechanics I suppose. I sorttt of understand how it works for spherical objects but that's about it.

I'm trying to program a physics system in processing atm and have been going over mechanics by myself in my free time

[left knoll]

Need help

[ember garnet]

A and C

[left knoll]

ye I got that

But idk rhe

Describe the sequence of transformations that maps rhe congruent figures

[ember garnet]

I guess to go from figure A to figure C you do a rotation by 90 degrees clockwise around the point (1,1) and then a translation by 4 units in the negative direction of the x axis

[left knoll]

Oh Ty

Mb ai gave me so many different Answer

Tysm appreciate it

[ember garnet]

you're welcome

there can be various answers to this question but the one I wrote I think is one of the simplest

[left knoll]

Oh

Dyk this ?

Cuz Everyone got different answer

Abc 😭

[ember garnet]

I guess it's a translation because of the labels of the vertices

also they are congruent, and hence also similar

[ivory wyvern]

for 3D rigid body mechanics I would reccomend Taylor and Thornton and Marion (both physics textbooks on classical mech). It will cover how to create inertia tensors and the basic ideas behind 3D rigid body mech

Heres the pdf that i use for my class for thornton and marion, though ive heard much better things about taylor (havent gotten to reading through it yet)

I believe chapter 10-11 will cover the content you are looking for

[stuck creek]

Thank you so much again!!

Awesome awesome

[ivory wyvern]

Yea np!

[pearl nacelle]

Hi what is the midpoint rule ?

[ember garnet]

you split the interval into n equal parts, and for each part you take the value of the function at the midpoint and multiply it by the length of each part. Then sum up all those products to get an approximation of the interval

[pearl nacelle]

ooooh thanks I understand wave it's like the same as a normal definite integral but without the limit, in the case of riman I just found this that explains it lul

But how could this be applied with the method of the fundamental theorem of calculus?

That theorem sounds super epic, lul

[ember garnet]

yeah that's the same thing

[ember garnet]

what do you mean?

[pearl nacelle]

No, the question doesn't make sense because the formula is exact, it was an idea xd

[ember garnet]

yes, it's exact, but you could get an approximation if you multiplied the value of the function at some point in [a,b] by (b-a)

[indigo totem]

yoo hello fellow EE major

and uhh, good luck with the more advanced math concepts eh?

🫡

[ruby lodge]

ye it's a glitch the devs have patched it

[stable dirge]

Can someone PLEASE help me with this lineal algebra problem?

[dreamy mist]

I would approach it by doing a small dimension version and try to either look at decomposition and spectral thm or look at rank thm, tips it would be helpful to start by quantifying what is a set and what is an independentl set and try to fit in.

[gentle creek]

I did a paper on that, lmk if you need some help 🙂

[gentle creek]

@winged cove

[winged cove]

Will do thank you!!
Taken a bit of a break from the work but gonna jump back into it this week >:3

[winged cove]

what did you do in your paper exactly by the way?

I'm super interested since I saw you said you're a CS student too!! :D

[pearl nacelle]

How i can do this derivative?

[fallen flax]

it looks like a iterated integral

i am asuming F(x) is the antiderivative of f(x)

and f(0) =0

so it will sinply be f(z)= F(whatever the upper limit is)

could u resend the question without cropping the upper limit?

[junior zinc]

can someone explain the limit comparsion test to me and help me with this

[echo jungle]

I think it is the last one.

I see it as you have a function g(x) that is larger than your function f(x). If g(x) converges than it kind of sandwhiches f(x).

You know that -1<sin(x)<1

So at it largest the numerator is 5 i think

x^1/3 > x^1/3 -4 so x^-1/3 > ( x^1/3 -4)^-1

[junior zinc]

this is the answer but i dont understand why

[echo jungle]

Im also confused. And i have studied improper integrals this year.

[echo jungle]

why a =1/3

Ask chatgpt

[empty orbit]

bet u cant teach me calculus

im willing to do whatever

anyone up for a bet?

no? alright text me if u wanna

[mystic thunder]

ok rohan

[dire aurora]

Why does google say theres no formula for a composite number when i can think of a = bc where a is a composite number and b and c are integers, neither of which are not equal to 1 or a? Am i wrong?

[empty orbit]

bro all you did here is prime factorization

i think google said so because its not necessarily a "formula" and more of just a theorem?

[empty orbit]

bro yes or no💀?

[fallen flax]

a composite number is a number which is not prime. if we have a formula for a prime we have composite numbers

for a prime watch a video on the riemann zeta function and u will understand why there is no formula

if u find one u will win a million usd from the millenium foundation

specifically the riemann hypothesis

[dire aurora]

Why is mine not a formula for composite numbers?

[dire aurora]

Why is it not a formula?

[timid delta]

What does formula mean?

Basically u r doing a factorisation

[timid delta]

It is a formula for composite but wont work for prime

Ok no it doesnt make sense to call it formula

Formula produces a value

What u just described is just a definition

[fallen flax]

because u are defining a variable based on 2 other variables which are intern dependent on the first

most other formulas are defined discreatly or geometrically

composite numbers are defined as möbius func(n) = (-1)^2x-1 =-1 for odd prime factors and (-11)^2x=1 for even

prime numbers also give -1 and 1

thus u cannot define a composite number at an infinite scale without excluding primes from range

and we cant find a prediction on primes so we end up with NO formula

[little plank]

Boys if anyone wanna ask me question you can i got air 250 in jee mains, i can spank up every question like its my gf

[silver quartz]

well u still got jee advanced coming

[fallen flax]

agar tera adv nahi nikla lath khaiga

a lot of olympiad ppl here who dint do good in mains

aukat me rehele

[little plank]

Ez brotha

[little plank]

They suck fr

[little plank]

Kitni rank heh teri?

[fallen flax]

tere bap ne kitna peya?

[fallen flax]

oh sorry bhai tere se bat karna bhari hai

[little plank]

Kya

[timid delta]

cringe

why put others down

I am proud of your achievements

[torn cairn]

Today's deals are hot! #mysales #bigdreams #Succcess

[exotic zodiac]

Can someone dm me the explaination

Thankyou

[light pollen]

Ngl it might be quicker for you if you use smth like perplexity and ask it, I don’t mean to be the person that nudges people off/to AI stuff, just saying as I think you’re more likely to get a satisfactory answer quicker that way, and if I knew I’d help but I’m not there yet, sorry

[quasi bridge]

starting from the inside, summation of 2p from p = 1 to n is equal to 2 * (n(n + 1)/2) = n(n + 1) = n^2 + n

arcot(n^2 + n + 1) = arctan(1/(n^2 + n + 1)) = arctan(1/n) - arctan(1/(n + 1))

so, summation of arctan(1/n) - arctan(1/(n + 1)) from n = 1 to 19 would be equal to arctan(1) - arctan(1/20) = arctan((1 - (1/20))/(1 + (1/20)) (iirc, might be wrong)

and after that just take the inverse and that'll be your answer

[remote widget]

i'd appreciate it if someone could please explain to me
also why is the normal force pointing to left shouldn't it be pointing to right?

[ivory wyvern]

You are right that the normal force should be right, you can account for that by just multiplying the magnitude of the force by -1

[ivory wyvern]

bro there are many students here in college, doing good in mains doesnt mean you can solve anything past calculus and basic linear algebra.

[signal vortex]

Hello, I'm trying to review my calculus notes and i can't for the life of me understand how they got to here TT TT

[signal vortex]

I tried it out again , I don't know if it's right or not

[fallen flax]

yo hol up what did u do?

[signal vortex]

integration

its for a forier series problem

[fallen flax]

yea i get that

what did u do in the chain integration?

i ligit blanked out and felt dumb

[signal vortex]

oh i used integration by parts

not sure if its standard procedure tho

then i simplified it
since the cos and sin have difficult values, the integrals look wonky

[fallen flax]

it looks right but i would have takes cos as first func

cauz ilate

and doen that table method

[ivory wyvern]

im confused, if you are integrating xcos(x) it will be 0, because of symmetry. Cosx is symmetric across the y axis, while x is not, so the terms should cancel out to 0

unless your function is -x when x<0, and x when x>0, in which case you can rewrite as this:

and a lot of the calculations become a lot simpler

[signal vortex]

iirc if you simplify my solution itll be 0, even my other formula results to 0

i have no genuine reason as to why we dont solve it till it gets to zero
but all chatgpt tells me that this is a standard answer for forier series

[signal vortex]

honestly yeah, unfortunately this works best for me cuz im clumsy lol that and its what we used all sem 😭

[little plank]

I can brotha

[ivory wyvern]

I know for a fact this isn’t covered in jee syllabus or any board exams

And the proof is not trivial

[little plank]

Homie hear me out u dumb or what? How can a person solve a question which hasnt been covered or even havent even told about concept

[fallen flax]

i am just curious, is this proof by contradiction?

like f(c)>=0 given f(c) continous in (c-r,c+r) ?

[ivory wyvern]

Then what do you mean? You only said you can solve any problem?

[ivory wyvern]

The proof comes down to using contradiction to claim the integral of f(x) is 0 on the whole interval, and then constructing a series of nested compact intervals of nonzero length recursively inside of the big interval. Then, using a property taught, you can more that there exists 1 point inside of ALL of the intervals, we can call this x0, which then allows us to say 0 <= f(x0) < e for all e > 0 (basically f(x) is arbitrarily close to 0). Then, since by definition f(x0) = 0, we get a contradiction as one of the given points is that f(x)>0 for all points in the big interval.

[little plank]

Gimi one more

[ivory wyvern]

If you just use ChatGPT, you are only cheating yourself.

[fallen flax]

abe bhai kal tera adv hai

focus on that

and gl

[marble parcel]

Does anyone know of any good YouTube videos on linear algebra?

[exotic zodiac]

I didnt understand anything after the first line 😭

[exotic zodiac]

I searched it up its 21/19

[fallen flax]

3blue1brown has a nice series

idk any other good ones cauz the ai/ml hype train has consumed the internet

[ivory wyvern]

Honestly, if you want to learn linear algebra properly I’d use this book. 3b1b is also a really good resource to visualize but I think if you want a really good understanding of how to approach actually doing linear algebra problems, you should work through this

[quasi bridge]

oh okay, lemme simplify it a bit

alright, so that is how you solve the entire most summation

now if you apply summation of arctan(1/n) - arctan(1/(n + 1)) from n = 1 to n = 19

a lot of the middle terms will be cancelled

and you'd be left with starting term and the last term

i.e. arctan(1) - arctan(1/20)

on simplifying that you'd get arctan(19/21)

which is equal to arccot(20/19)

and at the end there is cot on the whole expression

so the answer would be 20/19

[little plank]

Pucha ni kesa gya...

[fallen flax]

muche pata hai kaise gaya

ab bits par dhyan de

agar iit mila to achi bat

[exotic zodiac]

thankyou!

[little plank]

Best on best gya heh saukha tha

[little plank]

Delhi mil jeh gah par cse 80% chance only

[fallen flax]

abe saale es leye to lha mene agar iit mile to achi bat

ghamand nahi rakhte

josaa councilling tak padhte raho

paper is always easy results are never easy

[little plank]

Mehnat ki heh to ghamand to bnta heh bhai

[little plank]

Jee mains results were easy thats why i got air 250

[fallen flax]

beta tughe koi nahi samjha sakta

[little plank]

Are bhai apki kitni rank heh

[fallen flax]

mere tau tere 250 aye achi bat

shabash

khush raho

demag pakana band karo

[dire aurora]

Is this a valid proof? Good enough to be marked correct?

[fallen flax]

thats not how u prove it

like for any inequality including am-gm, try to think in terms of convexity

the left part is a linear function while the right part is a concave dipped function

it will converge at x=y if u know what i mean

take log on both sides and the inequality is preserved

then either polya or jensen inequality can be used to prove it

so (x1+x2 +x3)^1/n= g

basically take f(x) = (e^1-x) -x

f''(x) >=0 with max at x=1

so u get inequality as

(x1x2x3.....)/a^n<= e^x1/n-1 •e^x2/n-1 ......

take the logs on both sides

and u will get a proper proof

[slender temple]

does anyone know anything about mechanical linkages, because I wanted to ask if the picture on figure a has any redundant constraints/joints?

[pine thunder]

yes it does in figure a

The two sliders (links 2 and 3) are guided both by the fixed guides (ground) and again by the slotted disk (link 4).

[stable oyster]

does it contain exercises?

[ivory wyvern]

Yep, and there are solution manuals online if you need

[blissful drift]

😶🤯

Mere to 89%ile hi aayi bs

[waxen pendant]

Bhai what book(s) did u use for maths while preparing?

[blissful drift]

Jo teachers btate gae matlab XI me thoda sa btate h SL loney and Irodov,,, but ho nhi pati thi zyada,,, HCV, Anurag Mishra,, Coaching Material,,None for Maths 😓 only coaching material

[blissful drift]

Mujhse pucch ke kya meri acchi thode hi h

[waxen pendant]

😞 koi ni bhai

[waxen pendant]

Bhai could u tell me the books that u used?

[blissful drift]

Coaching material start to end solve krlo,, and fir jb vo na ho jae each and every question tb books pe aana

Mujhe sbne yehi advice di h aaj tk

[waxen pendant]

Bhai maine koi coaching ni join ki hai

Not even online

[little plank]

Physics wallah modules + hc verma for physics, i relied on modules and a few years pyq for maths

[little plank]

First priority coaching material

I never had backlogs so yea...

[waxen pendant]

is coaching really required? or is self-study OK?

dude can i dm for some advice if u don't mind 😭

[little plank]

Well people can crack jee without coaching but you know those people are 1 out of 15 lakh

[little plank]

Sure but I might be busy.

[steady crow]

Does anyone know a good video that can explain gamma and beta functions. A good textbook works too . It’s going over my head and most YouTube videos are not in depth

[weak lotus]

what is it that you do not understand? I can try to help you

[weak lotus]

this seems low-key good, has been a while since i saw them.
I do remember examples made them more clear

[mystic thunder]

how do i solve [x]+{x} >= 0?

[ember garnet]

what do those brackets mean?

[mystic thunder]

shi

[] greatest integer function, and {} fractional part function

[ember garnet]

{x} is defined as x - [x] ?

then your inequality becomes x >= 0

[mystic thunder]

oh you are right

thank you i forgor about that

i was tryna solve it w graphs and shi but ye tysm

[mental creek]

discrete mathematics is painful

anyone have a good way to differ between permutations, combinations, selections and any other ennumeration techniques...

[weak lotus]

Do you get the central notion concerning repetition and order?

If so, do you have difficulties with selecting/knowing when it is applied?

[mental creek]

im still learning

[mental creek]

my main issue is the like 5 different ways we have learnt are spread over multiple documents and i just want something that makes it easy to see which one to choose and when

[mental creek]

but yes to answer ur question...

[weak lotus]

im sure you can find some online, wait

[weak lotus]

i found this in my lecture notes

left side, top to bottom:
non-order
order

top side, left to right:
without return
with return

central notion is the same i think

[strong igloo]

what resources could i use to improve my math skills as someone who sucks at math

[fallen flax]

there are many

of calculus there is professor leanord on yt

for algebra i guess khan academy was good but idk now

there are many opensource materials like mit opencourseware and harvard public resources

[strong igloo]

Thank you

[fallen flax]

and 3b1b makes good visuals

[fallen flax]

welcom :)

[strong igloo]

I was looking to start over from algebra since i wasnt too good at it

then i failed statistics

[fallen flax]

i would suggest you use books

IMHO mir mokva and eastern bloc materials are yhe gold standard

cauz they were crazy for the IMO

[strong igloo]

i see

[fallen flax]

u can find pdfs in any large archive

internet archive,zlib and stuff

those books are prolly the only good things the ussr produces which benefited humanity

[steady crow]

I don’t understand how exactly we ended up with that definition. I think I need to read the proof to the function ? The pdf is pretty helpful but I still don’t get how exactly we end up with the gamma definition integral.

[weak lotus]

Imma look at a different proof, I'll send it later. Not accessible rn. I'll let you know!

I have a proof somewhere and the intuition behind it

[blissful drift]

find the number of ways in which 6 persons out of 5 men n 5 women can be seated at a round table such that 2 men are never together.

pls help with this question

[light pollen]

I went over it rq, looks right to me, was too tired to sit down and think w a headache

https://www.perplexity.ai/search/find-the-number-of-ways-in-whi-3Mqt1fPrQXauuYta5CB3hg

hope it helps :)
Keep in mind it dissapears after a couple hours/days, but u can use it anytime, just be super careful w maths

[obsidian spire]

Nah man you kind of did it backwards. You started with assuming the result you were supposed to prove was true. You want to start with something that is just fundamentally true from which you can work towards the result. (a-b)^2 >/= 0 is an example of where you could start, since any real number squared is greater than or equal to zero. Then you could do all that manipulation to get to your result.

Starting with what you want to get and working backwards to something fundamentally true is a great way to find the right steps to prove something though, in the opposite order. Otherwise it can be hard to see what 'correct fact' to base the start of your proof off of.

[obsidian spire]

I agree with many of clumsyoof's recommendations. I think prof leonard does some more basic math stuff too. Lots of free material, and free lecture notes available these days. You can check your work through a solutions manual, or people who like to answer questions on here.

Probably you want something like 30 minutes of problem solving (or 10 problems?) each day, and 30-60 minutes of reading, minimum each day.

[covert hatch]

idk it doesnt seem logical to me

i dont think 5 men and 1 women could sperate them and not make them seat close to each other

like i think it should be like that correct me if i am wrong

[light pollen]

assume 0 to 5 men is a case, from 1 to 6

0m, 1w => case 1
1m, 2w => case 2
....
5m, 1w => case 6

[covert hatch]

yeah i understand, what i cant understand why it said possible, shouldnt it be impossible ?

[light pollen]

if you go down a little from there, you'll notice we only take case 2, 3 and 4

[covert hatch]

just noticed

[light pollen]

that bit is indeed a bit confusing, i didn't get it myself tbh, but it does the calculations right

[light pollen]

the rest of the cases are not taken into account, because the constraint, not having 2 men together, wouldn't be met

[covert hatch]

the calculation i agree with it is just the table that is confusing

[covert hatch]

oooh

[light pollen]

ignore the right bit of the table, and the last row, and you're good

[covert hatch]

thanks lol

[light pollen]

case 2, 3 and 4, meet the criteria though:

1 man, 5 women
2 men, 4 women
3 men, 3 women

thus, you see that the combination for cases 2, 3 and 4 are calculated

and where it says Step 3: Add up all cases, well, it just adds them up

hope it makes more sense now, feel free to ask for any further clarification though ;)

[covert hatch]

yeah you did clarify it for me i appreciate it

🫡

[light pollen]

glad to hear :)

[mental moth]

what are good partial differential equation online courses / textbooks

[ivory wyvern]

I would first make sure you have a good background in ODE's and writing proofs, as both will be necessary. These are some books to get freshed up on ODE's:

(a) Hirsch, Smale, and Devaney's Differential Equations, Dynamical Systems, and an Introduction
to Chaos (currently in its Third Edition).
(b) Michael Taylor's Introduction to Differential Equations (currently in its Second Edition). An
old version of the textbook is available for download on the author's website:
https://mtaylor.web.unc.edu/notes/math-524-second-semester-ode/
(c) Strogatz's Nonlinear Dynamics and Chaos (currently in its Fourth Edition).

after that, if you are confident you have a good grasp upon the material and can write proofs for the theorems, you can move onto:

(a) Lawrence C. Evan's Partial Differential Equations https://math24.wordpress.com/wp-content/uploads/2013/02/partial-differential-equations-by-evans.pdf
(b) Michael E. Taylor's Partial Differential Equations I: Basic Theory

i do stress though you HAVE to be comfortable with writing proofs, and skipping rigorous study and jumping to PDE's is simply not possible

[mental moth]

thanks!

[sinful narwhal]

do you have any recs on Fourier series and transform?

[ivory wyvern]

Considering you are in ECE, id reccomend these resources (in order of usefulness to you)

(a) Lecture Notes for EE 261 at Stanford: The Fourier Transform and its Applications
https://see.stanford.edu/materials/lsoftaee261/book-fall-07.pdf
(b) Stein and Shakarchi's Fourier Analysis: An Introduction (Princeton Lectures in Analysis, Volume 1)
(c) G.P. Tolstov's Fourier Series https://archive.org/details/tolstov-fourier-series-1962/mode/2up
(d) Fourier Analysis and Other Tools for Electrical Engineers: A Practical Handbook https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=1029&context=books

TBH I think the best resource is literally just going through college courses in signals and systems, as you will find the most useful applications of these ideas there. For example, MIT OpenCourseWare has this course: https://ocw.mit.edu/courses/res-6-007-signals-and-systems-spring-2011/pages/lecture-notes/. Just reading through the lecture notes and using the help of above textbooks and youtube videos on the subject (of which there is plenty) will get you to understanding in this subject.

[ivory wyvern]

https://www.youtube.com/watch?v=gZNm7L96pfY&list=PLB24BC7956EE040CD
for the lecture notes for EE261 at stanford, heres an associated playlist with video lectures of very high quality

[sinful narwhal]

thank you so much! :D

[indigo totem]

i love my man fourier

he a real g

[sinful narwhal]

currently in a love-hate situation xD
learnt it all last week and i have my exam next week... its just too much information

[indigo totem]

i learn fourier transforms next sem, along with z-transforms, DFT, FFTs, etc

i learnt about fourier series in my math unit this sem, one of my favourite topics

[sinful narwhal]

i'm currently learning it in two units. signal and systems theory and calculus 4. i've also learned Laplace and the z-transform... they're honestly extraordinary topics, but it frustrates me a bit not to have more time to master them

[indigo totem]

whats calculus 4?

australian universities (or at least my one) has engineering math and advanced engineering math lol

[sinful narwhal]

you can call it engineering math yea ahahah
i guess universities just give it different names

[indigo totem]

i love math

except when it becomes theoretical

then its cringe

[sinful narwhal]

for real! my calculus 3 professor would literally makes us WRITE in our exams. he would ask "what can you say about Taylors series?" "is this phrase true or false?" like- let us do actual CALCULUS

i understand theory is very important, but ill leave that with mathematicians

[indigo totem]

thats a really unique question lol

luckily all my exams have just been "solve this" or "evaluate this"

[dense rapids]

I thought calculus 4 was real analysis, though

[junior zinc]

what australian uni do u go to

[hard tartan]

wth 😂 😂 😂

[sinful narwhal]

nah thats literally calculus 1

calculus 4 is all about differential equations

[sinful narwhal]

i know... it was ridiculous ;-;

[dense rapids]

I see

[indigo totem]

its one in melbourne victoria, wont say the actual name here tho lol

[junior zinc]

ahh ok ok

[lunar skiff]

Guys are there anyone have an idea?

180-172.795=7.205 am i doing something wrong?

[tulip egret]

no

you're doing it correctly

look, your entered answer is exactly the same as the answer preview

ask your teacher if they can correct it on the teacher account

[lunar skiff]

Oh ok, thank you so much.

[tulip egret]

no problem, they should be happy to change it for you since your answer is quite literally the same as the answer expected

[lunar skiff]

Well as I understand answer preview is just preview of answer that I entered, I mean it is not always true answer. But as you said, there is no possibility of other answers. It is weird. I think they did it wrong as you said again.

[tulip egret]

oh, is that so? i thought it was the expected answer, my bad
but yeah, in this case it seems like a possible computer rounding error that you can't possibly be expected to account for

at three significant figures, your answer is totally correct

[lunar skiff]

Yes it is the point

They don't want more than three significant figures and I did it according to that

I think it is their fault so I will send an e-mail 🙂

Thank you again ❤️

[paper reef]

can anybody help me

[dense rapids]

CMIIW

[paper reef]

Thank you so much

[gilded plaza]

Anybody know specifically why they simplify to the highlighted part in this situation? Like it kind of makes sense to me but idrk how to apply it

[ivory wyvern]

Are you talking about the reason they move sqrt15 to the top? If so, it’s mostly just the way more preferred by teachers, and it’s equivalent because you are just multiplying both the top and the bottom by the same number, sqrt 15, so that you can get a whole number on bottom instead of an irrational number

[gilded plaza]

ohhh gotcha, tysm!

[river tree]

Hey guys do you know any good calculus playlist on youtube that teach calculus really good. I have semesters approaching and I can't find good recourses online cuz im not habitual to reading math books. Please help.

[fallen flax]

professor leonard on yt

[river tree]

Damn he got muscles

[dire aurora]

@obsidian spire sorry for the ping. I just wanted to ask you: when asked to approve this result, would it still be a valid proof to start from both ends and meet in the middle like they have done in the photo? Or is this also the same as assuming the result, which is invalid like you told me before?

Or is meeting in the middle valid because no result has been assumed or shown until the very end where they do in fact meet in the middle?

[obsidian spire]

When proving equality, often you have to prove things in two directions. 'Given this value A, I will reach the other value B', 'given value B, I will reach value A'.

They shortened the proof by showing, given one or the other, they are equal to the same value. A=C, B=C, then by transitivity, A=B.

It is possible for one value to imply another, but not the reverse. Like say (3)^2=b-> b=9, but 9=a^2, you could have a= -3 or 3. For example. Proving it in both directions is often needed for equality of numbers, sets, etc. Especially for things defined by a is true if and only if b is true.

[dire aurora]

I see. When a question asks to prove it probably means both directions and when it asks to show, its probably either direction. And sometimes, just working in one direction is sufficient to prove both directions.

Let me know if I got it wrong. Otherwise that was very helpful. Thanks!

[indigo totem]

seeing this reminds me of why i love complex numbers and phasors

use em frfr

[dire aurora]

I don’t understand. Could you explain?

[obsidian spire]

Whether you need to show in both directions or just 1 its usually about the wording of what youre trying to prove, the logic of it. The logic dictates what is needed to prove a statement is true.

'If p then q' statements can only be false if p is true and q is false. So you assume p is true, and show q must be true, which by logic proves it cannot be false so it's true. Many one way proofs are these sort of statements.

If p then q + if q then p, aka p if and only if q, are the sort of statements you usually need 2 direction proofs for.

Get into logic and truth tables to see more of the mechanisms of proofs

[obsidian spire]

What do you guys think of sage math?

[dire aurora]

Got it

[dire aurora]

These equality proofs don’t have much wording but i know what to do for questions with more wording

Thanks!

[dire aurora]

For a question like cos(2x) = cos(90-x), where 0<x<360, how do i know which quadrants 2x should be if i want to take the inverse cosine of both sides, without refering to the graphs of cosine and sine?

I can use identities to manipulate that equation into (-2sinx+1)(sinx+1) = 0, the cases of which i know exactly which quadrant x should be in by looking at the right hand side of the equations formed by making the ratios alone the subject, which will always contain a constant. But when the right hand side isnt a constant, how am i supposed to know which quadrants the arguments should be in?

[dire aurora]

Okay never mind. ChatGPT explained it to me 👍🏼👍🏼

[slender spear]

The sum of the numerator and denominator of a fraction is 14. Numerator is 4 less than the denominator. Find the fraction

The length of a room exceeds its breadth by 3 meters. If the length is increased by 3 meters and the breadth is decreased by 2 meters, the area remains the same. Find the length and breadth of the room.

Solve x + y = 2 x - y = 0

The area of a rectangle gets reduced by 9 m² if its length is reduced by 5 m and breadth increased by 3 m. If we increase the length by 3 m and breadth by 2 m, the area is increased by 67 m². The length of the rectangle is
1)9m
2)15.6 m
3)17 m
4)18.5 m

If the equations 3x + 4y = 12 and (a + b) * x + 2(a - b) * y = 3a - 1 has infinitely many solutions then a and b satisfy the equation is
a - 5b = 0
5a - b = 0
a + 5b = 0
5a + b = 0

[slender spear]

@candid moth

@candid moth The sum of the numerator and denominator of a fraction is 14. Numerator is 4 less than the denominator. Find the fraction

/calc The sum of the numerator and denominator of a fraction is 14. Numerator is 4 less than the denominator. Find the fraction

[slender spear]

Thanks!

[left knoll]

Have to study math topics entirely from YouTube for a while, running into doubts and I end up switching videos in that case. Not able to cover enough ground due to that. I can send questions here right?

[slender spear]

Sure!

Ofc man, that’s what this is got

[left knoll]

Yes I mean I just wanted to be sure because I am in a MESS 😭

[slender spear]

Oh it’s Alr, sry if I made u sad or anything

[slender spear]

Which grade r u in if I may ask

[thick copper]

I did not cover this in class

[quiet burrow]

anyone know ai for math but not chagpt

[obsidian spire]

You multiply vector one by an unknown integer a, and vector two by unknown integer b. Add the two vectors with these variables introduced, see what values allow you to reach 71 for x and 33 for y.

[vestal tide]

photomath pro

[indigo totem]

you can convert a sinusoidal function to a complex number and then a phasor, and then you can use basic multiplication and addition to simplify it down, and then convert it back to a sinusoid

[left knoll]

[split mural]

Can anybody help me with stats?

[outer hull]

What did I do wrong? - Dimensions & dimensional analysis

[lyric leaf]

@outer hull in the equation give, the denominator is c^3 not just c, also i think going from the second to the third line theres a small mistake in copying down a number

[left knoll]

Someone solve

[ember garnet]

270 with leading zeros allowed, 243 without it

[true hemlock]

a bit of a desperate attempt: I waited too long to study for two exams i have for my online classes. One of them is calc 2 and idk if I'll do really well on it. Any tips on how to salvage my grade/fix my mindset before I inevitably have to take the exam?

[lilac jungle]

Hi! My two cents;

1. Calc2 is really about mechanical practice and quickly recognizing how are you supposed to tackle that specific type of problem, so try to have a battery of problems with most common strategies
2. If possible check the specific examples given in class or your guide book, because much of calc2 are variations of the examples given (granted more obscure or difficult but still similar)

If you want to chat or some examples of what I mean feel free to dm me.

[true hemlock]

Thank you!

[obsidian spire]

Depends on how much time you have. The way id do it with very little time is go over the theorems to make sure you can remember them on the chapters your class covered. Then do practice test. Then go over homeworks.

If its really not making sense id say read through the chapters first to see what is actually going on.

If they dont follow the textbook closely go over your lecture notes instead of the textbook for theorems and to understand

[keen walrus]

Can someone help me with this problem?

[ember garnet]

integral of 2 pi x [g(x)-f(x)] dx from x=5 to x=6

[exotic matrix]

Is that geometry

[zinc zodiac]

hellooo can someone tell me where i messed up TvT

grade 11 functions btw, if its illegible i can type it -v-;

answer is supposed to be 1/35b but im not sure where the mistake is :'D

[ember garnet]

your mistake is on the third and fourth line

on the third line, when you write the division explicitly, (49 a^-4 b^2) should all be in the divisor.

when you turn the division into a multiplication by the inverse of the divisor, the inverse of the divisor should be 1/(49 a^-4 b^2)

the a's cancel out and the b is in the denominator

[zinc zodiac]

i was trying to get rid of the negative exponent though, which is why i split up the divisor so i could flip 49a^-4/1 to 1/49a^4

[zinc zodiac]

ohh right

thank youuuuu :D

[zinc zodiac]

could you explain why this is wrong though ;v;

[ember garnet]

if you don't wanna have negative exponents then a stays in the numerator after inversing it by just changing the sign of its exponent

the inverse of a^-4 is a^4

it doesn't go to the denominator

[ember garnet]

so you could write this 1/(49 a^-4 b^2) as a^4/(49 b^2)

the a's still cancel out

[zinc zodiac]

i was taught that if you had like x^-y you could turn it into a fraction with 1/x^y

[ember garnet]

yes that is true, however in your problem you are taking its inverse also

[zinc zodiac]

mm alright one sec lemme fix it

yyayay i think i did it -v-

[zinc zodiac]

thank youuuu, ill be more careful looking for inverses w/o needing to flip noww :3

[ember garnet]

yes, that is correct now

but if you insist on getting rid of the negative exponents first, you could do it like this. It's the same thing

so first you take rid of the negative exponent and then you inverse, or you could first inverse and then change the negative exponent, better to do them one at a time so you don't make accidental mistakes

[zinc zodiac]

ooo alrightt

[zinc zodiac]

yes i will write out each step moving forward -v-;

[ember garnet]

you're welcome :)

[zinc zodiac]

this makes me so unreasonably happy i love that you can just kidnap the negative part and yeet it to the other side of the fraction lmao

[ember garnet]

hahahaha yeah that's an interesting description of what's happening there 😆

[radiant mango]

hello

im just a 9th grader

[twilit crane]

cool
welcome

[hardy tiger]

Same here

[zinc zodiac]

helloooo i need help againnn -v-;

apparently the only thing I got wrong was the 8 in the final answer should be negative

from my understanding though, the sec135 is negative but because its subtracted it becomes positive so its added..

[ember garnet]

It's not the sec135 that is subtracted but the square of sec135. The square of sec135 is of course positive. So you are subtracting something positive. So in the end it should have a negative sign.

[zinc zodiac]

isn’t sec135 -√2 though ;v;

the negative sign is left out from what I know, the square cancels out the root, so then its subtracting -2

[ember garnet]

it's - [sec(135)]^2 = - [-√2]^2 = - (2) = - 2

[zinc zodiac]

so the square cancels out the negative and the root?

[ember garnet]

yes, this is a property of exponents

(ab)^2 = (a^2) (b^2)

here you basically have a = -1 and b = √2

(-√2)^2 = (-1 √2)^2 = (-1)^2 (√2)^2 = (1) (2) = 2

[zinc zodiac]

oh true i didnt think of it like that

alright then thank youuuu -v-

[ember garnet]

any real number squared is positive, or at least not negative

[radiant mango]

niceee

[left knoll]

complex numbers are exception, aren't they?

[ember garnet]

true, I should have said any real number

[bold ibex]

how do i find out the e value of 0.171 * 10^37 using a scientific calculator

[ivory wyvern]

In scientific notation that equivalent to 1.71e36. We find this by getting one digit in the 1s place, and the rest will be a decimal. Then e will be the value that you put into the exponential of 10^36, or 36.

[dire aurora]

Could someone please explain the solution to this question?

[winged cove]

hm

got it, just gonna write some stuff down

[blissful nexus]

first plug the values in to see if they work

if they don’t find left and right side limits

also consider like the biggest term to find this limit

so as x goes to infinity does (tan x) ^2n get larger than x^2?

actually idk this question is weird

i’ll see later

[ember garnet]

Is this vector notation? If so, it should be D, but the question should also state that points A, O, and C are collinear

[maiden lake]

Why is your name iamphysics lol

[ember garnet]

lol what's wrong with it?

[dire aurora]

I dont get why the answer is D

[ember garnet]

why do you say that? did you find something else?

[dire aurora]

no. I just have no clue how its any of those options

ill try again

no clue

do i need to find an expression for AB?

[bright finch]

How the fuck do I remember this for my exam. This is chaotic

[ember garnet]

think about the geometric interpretation of the dot product

in the answer D, the projection of 2a onto b is b itself

[dire aurora]

we dont know that its a right triangle tho

[ember garnet]

because the angle ABC is a right angle, because AC is a diameter of the circle (which is not explicitly stated in the problem but it should, because without it you can't really answer anything)

[dire aurora]

lmaooo

lame

[ember garnet]

if AC is a diameter, it is a right angle

if it isn't, no statement has to be true

[dire aurora]

B is a point on the circle, so triangle is not necessarily right

but thanks for helping get to the bottom of that. the question was poorly written

[ember garnet]

the only necessary condition for ABC to be a right angle is that AC be a diameter of the circle

[dire aurora]

Oh wow

I was never taught that in Australia so that pretty cool to me

[dire aurora]

Is there a nice way to derive this statement so i can rememeber it better?

could it be related to something like the law of cosines?

[ember garnet]

it is Thales's Theorem
https://en.wikipedia.org/wiki/Thales's_theorem

[dire aurora]

do you personally remember it by the thing itself?

chatgpt gave some cool derivations

[ember garnet]

To use it in your answers, you don't have to derive it or prove it -- it was proven more than 2000 years ago in Euclid's Elements

unless the question specifically asks you to prove it

It's an established, famous, and widely used theorem. I just remember it.

[ember garnet]

you haven't learned this trick?

the only thing you need to remember is the sign flip for the middle term

[maiden lake]

Nothing
Like to know the reason behind it

[ember garnet]

because I have a degree in Physics

[bright finch]

this is huge thanks

[maiden lake]

That's a ton
Congrats

[ember garnet]

Thanks!

[sinful sedge]

Very easy bro, js solve 10-15 questions and then you are never gonna forget it

[bright finch]

Yeah the method listed above helped alot

Anybody know how I can identify and draw this equations conic

(I translated from portuguese dunno if im saying this correctly in english)

[ember garnet]

You need 3 dimensions to draw it, it has 3 variables. You can do it in desmos.

[zinc zodiac]

hellooo can someone help me clarify the answer to this -v-;

ik its a geometric series, so the formula for it is [a(r^n-1)]/(r-1)

my teacher is insistent that the answer is 33140, but i dont see how thats right because it wouldnt even count the emails from just two months; even without any new users, the amount of emails should be at least 342,000 🫠

[ember garnet]

it's around 777k?

[zinc zodiac]

yeah ok cause thats what i got too TvT

[zinc zodiac]

alright yeah i got 777,216 too

welp i dont think my teacher is gonna accept that she's wrong and give me the mark but validation is nice -v-

[ember garnet]

show her this table above, it's undeniable

[zinc zodiac]

i sent her an email this morning, if she responds with more defense for her answer then i will

thank youuu :]

[ember garnet]

I'd like to know her defense too :P

[zinc zodiac]

i think she used 0.14 for r in the formula

but its meant to be 1.14 and im pretty sure 0.14 just gives you the amount of new users

[ember garnet]

yeah

[ember garnet]

that would mean that the site loses 86% of its user base each month

after 9 months they would have 0 users

[zinc zodiac]

that genuinely made me lol omg

realistically though i bet they'd still send emails to users that left 🫠

[ember garnet]

yeah true lol

[blissful nexus]

lmfao i read through this 😭

why the teacher being so adamant

💔💔

[zinc zodiac]

sadly, lots of teachers i know dont like admitting theyre wrong, especially math teachers TvT

i will let you guys know if she admits though ^^

[blissful nexus]

omg lowk

reminds me of this one time

i used some notation in math and my teacher crashed out even tho it pretty much meant the same thing and made me write what she wrote

[zinc zodiac]

lmao T-T

my teacher is also really strict on notation and stuff, though honestly i get it cause the course is online so its much easier to cheat -v-

[blissful nexus]

😭 💔

i took pre calc online and checking my work was very easy 😅

[blissful nexus]

brah but when i use the same notation when im talking to people who do math every single damn day and have like equally as important experience is fine 💔 🥀

its suddenly invalid when i use it in her class

[zinc zodiac]

hhhh we love stubborn strict teachers 🫠

[blissful nexus]

😔

well its okay im done with her class anyways

[bright finch]

Guys the question I have is "Identify and draw the conic given by the equation:"

And when i put said equation in desmos all it gives me is this:

Is this what its supposed to be?

only reason it even shows up is because of that z = 1 slider thats not even originally in the question I had to add it to see something

[stark onyx]

thats a 3d equation

use desmos 3-d, not desmos

https://www.desmos.com/3d

[bright finch]

That was it tysm

[weary olive]

(\log (\sqrt{a})-\log _{\sqrt{5}}(a)=2) need help

i already change the base surd 5 to base 10, i also done substitute the loga onto an unknown but after that i dont know what to do anymore

got a various answer, but none are correct by the validity test

what do you think

hotel? trivago

aint nobody reading this shit dawg :/

[left knoll]

@weary olive do u know how to solve atfter last step?

[weary olive]

Yesssss

Thank youuuu

[zinc zodiac]

SHE SAID SHE WAS WRONG AND SHE GAVE ME THE MARK

[ember garnet]

good for you! she finally folded haha

[left knoll]

w teacher

[rigid mist]

Can anyone help me with this. I dont understand

and if anyone knows any good resources for studying Logic that'd be very helpful

[timber trail]

Has anyone ever taken or will take the Putnam? insights would be greatly appreciated

[weak lotus]

C is correct because the biconditional captures mutual implication

(if im not mistaking)

First one (your answer) is wrong because CPOS (contrapositive) is the other way around

i.e. The formula not X --> not Y is not logically equivalent to X --> Y. The correct contrapositive is not Y --> not X, and not; not X --> not Y

idk if i make sense

lmk

what can be good is finding examples and work with those examples

make it a lot less "abstract" if you see what i mean

gl!

[rigid mist]

tysm, i had a face palm moment when i saw the CPOS switched

but the weird thing is option D is also correct

It says that in the answer booklet but doesnt explain why. Ig the answer booklet could have a mistake in it

[weak lotus]

Now you know it. Mistakes are the best!

[rigid mist]

Is option D correct also btw?

[keen walrus]

Hey guys, I need help getting started. How would I solve this problem?

[left knoll]

it is a standard formula- the answer is log |x+ (x-a)^1/2 | + c.

you can rewrite the integration as dx/sqr( (x)^2- (5)^2)
where, your a=5

or you can put x=5 sec theta to solve the question

[tranquil yarrow]

how come /tex isnt available (for me at least)

[left knoll]

are u asking why not put x=tantheta?

[tranquil yarrow]

Oh no the #how-to-use-math-bot channel suggests there’s a command called /tex to put tex in but it doesn’t come up for me

[left knoll]

ah, i see. try using forward slash

'/tex'

[mortal chasm]

Why is there a 0x^3 and 0x where did that come from

[left jungle]

oh those are just placeholders

[left jungle]

a polynomial is an expression of the form a_n*x^n+a_n-1 times x^n-1..., when youre dividing you need to take this into account or else when you subtract, you will be subtracting the wrong degrees

[tulip egret]

never ever forget them when you do polynomial long division 😞

[left knoll]

doesn't matter if u write or dont write 0x^3 or 0x. you can still solve. 0's are added to eliminate confusion.

[mortal chasm]

Yh i still got the same answer in the end

[left knoll]

congrats!
if i am not wrong, the equation is not fully divisible by x-3 right?

[mortal chasm]

Theres a remainder so yh

[paper reef]

How do we differentiate it when the integral symbol is alr there

[narrow tundra]

this variation of the leibniz integral rule should work

[paper reef]

Oooh..

Thanks I will try

[timber trail]

Anyone here that has aspired to or has taken the Putnam? If so, could you dm me. Your advice would be greatly appreciated

[umbral thunder]

since this is definite integration i think u have to solve the numerator first and then u will get a normal limit with x only as a variable, that'll work since the limit only asks x -> pi/2

[paper reef]

Oooohkii thankss

[mortal chasm]

why is there a 3x i dont get it

full question

[ember garnet]

expand (x+2)(x+1)

[weak lotus]

cant say the answer, cuz there is a whole lot to calculate, but can try and help you through it

if you take the first term, you can denote it as X
second term as Y

You can write x with the help of a geometric series and then you could take the real part of that expression, instead of expanding, you coudl - i think so, has been a while - just calculate it with numerical (dont know if you have a calculator lmao)

you know cos of pi/6
you calculate cos of k.theita
add those
put into X and you have p
use p to find the rest of the answer

[carmine solar]

Thank u

[vivid coral]

Can someone tell me what 5^+ means? Thanks, this is for Calc AB preparation

[weak lotus]

going to postive infinity

how do i say this

to the right of the x-axis

like you approach it from the right

💀

[misty belfry]

Can someone explain why on the LHS beta become negative beta when using the cofunction, max confused

the last and second last step

I got itttttttttttttttttttttttttttttttt. Genuis of algebra. god some might say. hahahahahahahah

[tired fable]

Approaching positive 5 from the right side. So like 6, 5.5, 5.1, 5.001, ..., but only from numbers greater than 5

[spiral wraith]

My approach to this problem is that arrange let's say men in n! ways
which will create n+1 gap and then I can use P(n+1,n) for arranging
But it seems wrong and I cannot figure out why?

[ember garnet]

With P(n+1,n) you also include arrangements that have one unfilled gap which violates the condition that the men and women alternate

It's just n! n! for when the first person is a man and n! n! for when the first person is a woman, so in total there are 2 n! n! ways

[spiral wraith]

Thanks bruv!

[spiral wraith]

Cant get this one!

[willow sparrow]

guys i have some trouble learning induction

( self learner )

[ember garnet]

what have you tried abou this?

[weak lotus]

Can help you. What's the problem

[spiral wraith]

I am not able to understand the question to be honest!

[ember garnet]

4-permutations means selecting and arranging 4 distinct elements out of N elements.
In this question, N is 100. With the given conditions, some valid permutations are:
for (a):

• 95, 1, 2, 3 (where k = 1)
• 11, 95, 12, 13 (where k = 11)
• 4, 5, 92, 6 (where k = 4)
• 7, 8, 9, 99 (where k = 7)
  for (b):
• 95, 1, 2, 3 (where k = 1)
• 42, 43, 44, 91 (where k = 42)

[spiral wraith]

Oh I get it now! thanks

[spiral wraith]

Need help with part D

[loud nexus]

you gotta make cases and solve mate

[willow sparrow]

sry Im late but I get that it's used in a lot of math important things but a lot says that it's unreliable specially that it can be that every case i pick the eq is right but it can be a coincidence , anyways i'm sure there is smth Im missing

[weak lotus]

can you elaborate using an example?

[rough mist]

Anyone know any good free courses for algebra based physics

Im gonna be taking a class with it including a lab so i kinda new a refresher lol

Or any good textbooks

[ivory wyvern]

https://www.learnedguys.com/uploads/files/239/IGCSE-Physics-Coursebook-by-David-Sang.pdf

This course is a really nice introduction

[maiden lake]

Fake

[ebon relic]

am i trippin or this question is wrong ?

[flat copper]

I'd say the answer is C, but I could be wrong

[ember garnet]

Yeah, it's 18

[ebon relic]

thanks

[left knoll]

can we say that one side is 18 units and remaining 2 sides are 9 2½ units each? @ember garnet

[ember garnet]

If by 9 2½ you mean 9√2, then yes.

[vague wadi]

Anyone have a good tool/way recommendation to self teach calc 1-3

[whole timber]

you can search for professor Leonard on Youtube. He has three playlists for calc 1-3. His explanations are very easy to understand and a good way to self study for calc imo.

[tulip egret]

<@&942391219206647828> i think this user was banned, but somehow this phishing message still remain 🤔

[tropic oyster]

thats strange. its gone most places. ill get it removed manually, thanks!

[tulip egret]

thank you !

[daring lotus]

Heyy guys, im bad at math and i want to start from 0, any recommendations?

[green swift]

i'd take the kahn academy test first to see where you are

hi all i am having trouble identifying if this limit exists or not for g(x) as x approaches 2 from both sides.

I am confused because I thought you need to look at both curves from each side to know if it exists or not. So it shouldn't exist since the other curve doesn't even go to positive 2 but my friends say otherwise.

Any input is welcome. thanks.

[ember garnet]

what do you mean the other curve doesn't even go to positive 2?

the limit exists in both cases

[ivory wyvern]

It going to 2 does not require continuity before, it just needs a small section to exist (of any non zero length) before x=2

[potent sundial]

please help with this

[left knoll]

put e^.. term as t

and then solve

is it 4x or f(x)?

[potent sundial]

its psi x

[left knoll]

could u send the question prrperly again?

[eternal elk]

nice

[cerulean dust]

yo i had a question from Graph Theory, let's say there are 2 graphs and their degree sequence is the same, same numbers repeated for the same amount of times (for eg. graph1 has deg sequence as 3,3,3,3,3 and graph2 has deg sequence as 3,3,3,3,3 - same number repeated for the same amount of times), in such case, can we call the graphs Isomorphic without taking the One-One correspondence of Vertices and Edges ?

[obsidian spire]

Check out professor Leonard on YouTube for the basics. Look for a textbook with solutions in the back to practice problems from, and read through the textbook sections if the problems aren't making sense. Write down math words and write out what they mean, then double check yourself every so often.

Start with the earliest level of math that is confusing you, no matter how early that is. Getting the basics figured out makes the rest a lot easier.

[potent sundial]

Im - Imaginary part. Please solve this for r=0.5 and theta= pi/3

[azure narwhal]

what have you tried?

hint: https://cdn.discordapp.com/attachments/1410309927318196296/1418763642106544228/1410308880495546453.png?ex=68cf4e1b&is=68cdfc9b&hm=66fdf2573a6ace70a3e6d32e83a90dde5e4d64fecf25e3a9fd4a2f72e4965a0a

[cinder moat]

This almost looks like you are supposed to to manipulate trigonometric identities

[tall knot]

alll u gota do is develop e^(i * theta) = cos(theta) + isin(theta) then multuply what u have at the bottom and the top by (2-2cos(theta))+2isin(theta) and try to isolate the imaginary part and the real part

[daring void]

Guys im so slow in math and i feel so left behind in class, when teach puts exercises that we should be able to do, other people finish fast and im still struggling with the first ones, what can i do??

[fluid heath]

Hello ! I think it is normal to feel so. Each have their pace and their way of learning. I advise you go home and redo the exercises you solved at school and try to solve others that are similar, by time you will be able to get faster and catch up with the rest.

[daring void]

Thank you for the fast reply, im trying to balance my hobbies with school, knowing everyday except Wednesday i go to school at 8am and finish at 6 pm, how often should i practice maths? And what about my other subjects

[fluid heath]

Try to practice maths after each maths session, be it in a break or when u go back home and rest. No need to do long sessions, just 15 to 30 minutes revising the lessons and exercises you had at class, then in weekends or whenever you can, look for exercises about the same topic and try to solve new ones, even if theh are challenging and if you couldn t solve them.just ask your teacher for help. Otherwise i can help !

[daring void]

Alright thank you, ill keep you in mind and ill try

[daring void]

Hey, just took my math exam today, i redid all the exercise she gave us the other day and turns out i was just not thinking, i understood everything and i answered to all the questions with no problem, hoping to get a good grade 🙏

Ill practice more often and share my progress!!

[fluid heath]

Good job ! Keep it up.

[azure wolf]

no math help?
damn
i feel like i have no purpose

[candid moth]

The renderer took too long to respond.

[azure wolf]

vro 😭

[candid moth]

The renderer took too long to respond.

[azure wolf]

can't seem to understand the significance of 1.45

Any help would be nice

[tall knot]

Could u give the full exercise?

[azure wolf]

It's from a poll i took (can't share)
just checking why the 1.45 exists... (couldn't find the proper correlation)

[woeful vale]

Hey, could anyone help me understand how to calculate the dot product and cross product based on the graph from Task 1? I’m quite confused. Thank youuu guys

[tall knot]

the dot means a scalar and the multiplication maybe means vectoriel?

[left knoll]

Any recommendations of apps or websites that give math lessons? Specifically for geometry? I'm starting a carpentry apprenticeship and would like to get my mental math skills better.

[elder socket]

tks

[ivory wyvern]

To calculate a dot product, split the vector into its two components (how much it moves in the x and y directions) and then multiply the x direction components together, and add them to the product of the y direction components. For example, for vectors <2,1>, <3,2> the dot product is 2 x 3 + 1 x 2 =8

you can see how to do the cross product by using this: https://www.youtube.com/watch?v=pWbOisq1MJU

[woeful vale]

Ah, thank you a lot; I figured it out after that. The exam went well

[left knoll]

glad to hear! if there was some angle give b/w the two vectors u could've solved it using sin theta and cos theta for cross product product and dot product respectively

[ivory wyvern]

nw, sorry i dont check the server too often so i couldnt respond sooner

[ivory wyvern]

do be careful though, the cross product equation using magnitudes and angles will only give you the magnitude of the cross product, not the vector quantity

[vernal sleet]

IF p and q are the roots of x square+px+q=0, then value of p must be equal to

a) 0,1
b)1
c)2

d)o,-1

[mystic thunder]

1?

[vernal sleet]

allow me to shatter your happiness

0,1

[mystic thunder]

nooooo

how

isn't products of roots = q

pq = q then p 1

dang

OH SHI

u gotta form a quadratic

equation

[vernal sleet]

bwahahahahahahahah

[ivory wyvern]

It cannot, as a side length will never be zero or infinity

[real birch]

Hi! Could someone please explain how to do question d)(ii) without using cross product?

[ivory wyvern]

Scam

@trail swift

Please ban these people

[tranquil yarrow]

Cartesian? Carti seeyuh

[potent oriole]

Hello im starting engineering and im really struggling my level is very bad im not able to solve problems so i always need to check the answer. I want to ask you about where can i find the answers like do u have an ai recommendation or books or YouTube channels.

[tropic lichen]

guys i have a multivariable calculus midterm on friday 💔 but lowkey i haven't been to class much and even when i do go i don' learn much. the professor is so sweet but it's her first time teaching multi and you can tell. and my roommate took multi last semester (different prof) and they said it was h*ll on earth. im actually cooked does anyone have recs for multi resources? we don't have any assigned textbooks, and the recommended ones are like a couple hundred dollars each and im very broke. please if anyone has taken multi or calc iii please help ❤️

[civic summit]

have you tried https://tutorial.math.lamar.edu/Classes/CalcIII/CalcIII.aspx

[tropic lichen]

omg wow this is beautiful. tysm this is so much more organized than my lecture slides

[civic summit]

no problem 👍

[indigo totem]

remember that you cant use the divergence theorem on an open surface and youre all good to go 👍

[opal frigate]

Hey!
I have rather basic understanding problem regarding Relations and Functions and was wondering if someone would have interest and patience explaining it to me. I struggle with the "It just is this way, so use this formula and that's it" explanation.

I am a bit stuck on the wording as I am learning in German so please bear with me... I am in my first semester studying Computer Science, the approach on this university is more practical than theoretical, but maybe a bit of theory would help me now.
We just finished up the topic "Relations" so when you have.. and I hope I m using the right words ... for example 2 Groups like A={1,2,3} and B={a,b,c} and a specific Relation R which includes some of the tuples from AxB, what properties the R has, namely reflexive, symmetrical, antisymmetrical, asymmetrical and transitive. I understand that and find it pretty easy. We also did the same with AxA, and R resulting from operations like <, >, =, and so on. As I've said, I feel that I have understood all of that. The problem comes up the moment I have some kind of function, f.e. f(x) = x^(2) -1, or the other way of writing functions like y=x^(2)-1, where your "groups" are Real Numbers on Real Numbers or anything like that. I think the trouble lies in me having trouble with the idea of tuples before like a being an element of A and b being an element of B so you have (a,b) and looking for (a,a) or (b,b) to figure out whether the Relation is reflexive, vs doing the same with (x,y) or is it in fact (y,x) meaning what is R->R (Real Numbers) in comparison to A->B, and so on.

I am online for the next 8 hours, is someone interested in helping me?
** OR can point me towards a course or something explaining that well of course <3

[weak lotus]

i think what might help you is the fact that a relation, denoted by R which can be denoted by a function y = f(x), where you have input - denoted by x, and an output - denoted by y, is ordered.

Lets say we have the following relationship:
B, denoting Bigger then
a, denoting an object, lets assume a human (the tallest person on earth)
b, denoting an object, lets assume a human (any other person on earth, different from the one denoted in a)

Then Bab, states that: (i)
a is bigger then b.

Consider:
Bba, following from (i), we can deduce that Bba, is incorrect.

Why is this imporant? because its important to concider the fact that relations are ORDERED. They have a property where it DOES matter what element you take from your collections.

So lets now, with this in mind go to your example of y = x^2 - 1.
this is actually a alternative way of writing Rab, what it does is SHOW what happens when you take an element from A, put it into a "box", where the box here functions AS the function, and what result you get.
You could represent the problem in your questions as follows:
f(x): IR --> IR, with f(x) := y = x^2 - 1.
So what you do is take a number from IR, but it into f(x) and you get a result, which is y.
maybe its more clear when you consider the following:
f(x): IN --> IR, with f(x) := y = x^2 - 1

this is totally different; because you cant take ANY number, since your building blocks are elements of IN, which are 0, 1, 2,....
if youd pick numbers from IR\IN, then you dont do what the function asks you to do, that why the tuples i.e. ordered pairs are crucial to keep in mind.

To see what the property of a function is, you look at the definition of such a property and apply the given relation to the definition.
Lets take transitivity as an example:
A relation T, is transitive if (a,b) E T and (b,c) E T, then (a,c) E T?
apply this to f(x) = x^2 - 1, with f(x) = x^2 -1
(b = a^2 - 1) AND (c = b^2 - 1), THEN (c^2-1)?

lets say a = 2, then b = 3, so (2,3) E IR

let b = 3, then c = 8, so (3,8) E IR

following from the definition, since (a,b) and (b,c) E IR, it follows that (a,c) E IR.
8 = 2^2 -1

--> not true, so T is NOT transitive

Hope this helps!

[opal frigate]

I am still reading (it's a bit of a struggle with the writing, so it takes time), but I think I am starting to understand. Thank you so much!

[tropic lichen]

alright ill keep that in mind lol

[vital kernel]

guys i need a little help in linear algebra

what letter (?) is that subscrit? that has a another subscrit that goes from 1 to d

I don't know that symbol at all

any idea?

[tropic lichen]

yeah idk how to decipher that handwriting. it's like x (subscript(j1)) right? then keeps going j2 j3? i wanna say it's like j lambda? lambda looks like the only greek letter that would match but it doesn't fit exactly especially that like loop(?). i could also just be completely wrong

[vital kernel]

yea bro but he (the professor) writes the lambda in a different way, and same thing for the j. hahaha impossibile to understand this symbol. i have decided to transcribe it as it is

thanks for the effort 🙂

[tropic lichen]

good luck dawg, lin alg is already crazy hard i can't even imagine trying to learn it if i couldn't read my professor's handwriting

[bright hatch]

any resources/tips on how to get good foundation in Algebra, Probability, and Statistics

[tropic lichen]

openstax has a bunch of free textbooks you can check out, and they're pretty good too. ive been using them for a couple of years now https://openstax.org/subjects/math

[tired ferry]

#math-help Can anyone tutor Differential Equations?

[wintry geyser]

Can anyone help me evaluate if I have transformed the matrix correctly?

[delicate osprey]

https://youtube.com/playlist?list=PLInywrvFyvq408vWA5OYXShA6rlT51TdS&si=zGgkLoHNrZ5QuSrx

[wooden dune]

should be right.

[tired ferry]

Thankyou so much!

[toxic wolf]

i’m freshman (15) and i don’t remember all of my multiples, which has lead me to rely on a calculator, how to relearn 🫩

i know 1s, 2s, 3s, 4s, 5s, 10s,11s and that’s it

[ashen girder]

l subject maths

every nightmare of engineers

[delicate osprey]

not really

[ashen girder]

Atleast for me:(

In engineering youre forced to study it in most of the countries

[left knoll]

then dont do engineering if u atleast cant dedicate yourself to it

theres nothing without maths

its the basic u can do if u r opting for engineering

[ashen girder]

im still studying it i never said that i wont study it

its just hard

[left knoll]

wuts this

[ashen girder]

im telling that i have to study maths

no matter

which country i am in

engineer requires maths

[left knoll]

sure u have to it has no corelation with country

kk gl

[toxic wolf]

So just do problems?

Alright thanks man

[potent oriole]

Hello i haven't touched solidworks. I need to learn it. I have one week off but also a huge backlog in maths physics so i can't fully dedicate it only 4h maybe. Do you have any tips please

[lunar mica]

anyone knows a AI that can scan a pdf file, then extracts a list of mathematical formuals in said file?

[eternal elk]

I've been struggling with this trigonometric identities for a week now, AND I JUST CAN'T UNDERSTAND

firstly I tried to understand the methods and then when I try to practice a problem, I just don't know how to begin

[pure oracle]

I think you should see lectures on it

[shadow mural]

hows the middle different from tje one on the right

[delicate osprey]

for the middle one u are twicing the value of g whereas in the rightmost one you are halfing the value. they are not equal

[shadow mural]

How r they equal

[ivory wyvern]

They are not, 1/(g/2) = 2/g. The left and middle are equivalent though

[bold prawn]

how do yall study math?

[sinful narwhal]

lots of practice

[cyan rock]

Try to look for the possible substitution in the expression. You may have to rearrange terms first.

[cyan rock]

Read textbook section, attempt problems from said section.

[weak lotus]

what is also fun is when you have a solution, is trying a different method. which helps you understand it more xp

[static pine]

each digit of a 9 digit number is 1. it is multiplied by itself. what is the sum of the digits of the resulting number?

[delicate osprey]

111111111* 111111111= 12345678987654320

the sum of resulting number is 9?

[tulip egret]

every digit is 1 and there are 9 of them
i trust that you've tried doing this already 🤔

[maiden lodge]

https://en.wikipedia.org/wiki/Repunit

Let R_n denote the repunit with n ones (e.g. R_3 = 111, R_9 = 111111111).
When n ≤ 9 there are no carries in the convolution that forms R_n^2.
Squaring R_n is the convolution of n ones with itself; the raw convolution coefficients are 1,2,3,…,n−1,n,n−1,…,3,2,1.
If n ≤ 9 none of those coefficients exceed 9, so they are exactly the decimal digits of R_n^2.
The sum of those coefficients is n^2 (because the sum of all entries in the convolution = (sum of the first vector)·(sum of the second) = n·n).
Hence for n ≤ 9 the sum of digits of R_n^2 equals n^2. That explains your example: R_9^2 digit-sum = 9^2 = 81.

[teal hatch]

about basic vector and i need help, tks for read hihi, i'm from Vietnam

[delicate osprey]

I used a scientific calculator

[void sail]

<@&942391219206647828> check this out

sorry for ping

bruh my friend was recently hacked and sent me the same exact messages lmao

[void sail]

again?!

screw it

<@&942391219206647828> im sorry for the ping again but it seems every channel is being hit with tis

[gaunt umbra]

do people know how to not click on suspicious links

[tropic oyster]

thanku

[void sail]

way less than you realise

[opaque wagon]

out of 150k members, it is to be expected to have at least a few compromised accounts per day

[stark plaza]

i want to brush up on all the basics of math is there any good sites i could go to to relearn it

[north linden]

prolly khan academy videos

pretty good summarisation of concepts

[fast torrent]

anyone online/?

[novel geyser]

Watch unacademy jee basic math english

[glad iron]

@everyone im really bad at math could some please just solve this because i dont understand shi

[tulip egret]

did you really have to try and ping 150,000 people to get help on simple interest

you have all the variables given to you, put them in your calculator

solve for A

A=850+(850 x 0.045 x 10)

[pearl sentinel]

U got all the values and formulas ig

Take 4 1/2 as 9/2

Rest is just substitution ig

[peak veldt]

optimization question I dont understand

I've gotten as far as (w+4)(h+2)

for the border

i dont get it tho

[left knoll]

its given w x h (area of flower bed ) = 646
so know u have a relation between w and h

let say A = (w+4)(h+2)

NOW PUT THE value of w in terms of h
and then evaluate

dA/dh = 0
.... as the minima or maxima would occur at the critical point only

the value of h that u will get will be either max or min value
if max .. then find out W using the earlier relation
if min .. u have ur answer

[peak veldt]

thanks

[solar bloom]

hello guys, can anyone help me with this? its statics of rigid bodies. I started at Joint A then B - H, im having trouble solving joint g or c.

[timid delta]

@solemn dirge

[umbral roost]

Linear algebra exam in less than 5 hours, someone pls help. (This shouldn’t be difficult but I’ve done this many times and either yield -52 or 108 ; correct answer is 52.)

[wicked gulch]

Sorry if it is too late

[analog dove]

heyguys i have to do a statistical analysis on a dataset for my econometrics class. requires R codeand OLS regression which i have done. in analysis i am doing t-tests, looking at confidence intervals, coefiicients, and p-values. and r^2 values. is there anything else i should talk about ?

[umbral roost]

All good. Is there any reason the signs are different?

Im assuming it’s related to the position where (-1)^ij

Not entirely sure how to conceptualize this…

[delicate osprey]

it is (-1)^i+j if I am not mistaken

[umbral roost]

You’re right sorry I forgot the +

Thank u guys for the help tho, really appreciate it

[timid meteor]

yall i need help plz🙏

[patent kite]

What have you tried? Or do you not have an idea where to start?

[merry crystal]

https://codeforces.com/problemset/problem/1199/B

guys please help me...

[spare ice]

how would one do this limit with substitution 😅

[nimble seal]

Can anyone help me understand Integration by Parts, prolly give a good resources that might help

[hexed cloak]

Just a quicker way using the sarus rule and a quicker expansion

The final product outputs 52

Also sorry for the terrible writing

[old delta]

https://youtu.be/3zLQfuMZMF4?si=yEqbYmJqCJC_Zzfh this video might help you

[spare ice]

ayyy okay thank you

[modest tusk]

Need some help going through this problem. Ive already found the critcle value from the t-table which is 0.561, but I dont know what to do from there

[slim juniper]

Anyone here know linear regression

[tropic lichen]

i have my discrete structures exam tomorrow and i can bring 1 piece of paper with me with notes on it. this is what i have so far, what do you all suggest i add? i have so much space and this is just the quick basics

[hexed cloak]

How much time have u guyys been working on these before the exam ?

[rancid plaza]

What year are you in?
This is very basics imo.
I'll recommend adding more amount functions. If any major theorem like the shroder bernstein are subjected. Write up proof steps.

I think this is more than enough (if this is exactly the domain that the exam is subjected to)

[raven galleon]

my brother.. chill out w/ the disparaging comment😭

[narrow pier]

Topologists?

I struggle with intuition when it comes to understanding what it means for a function to be continuous in topology

[fallen flax]

the intuition for continuity is same regardless of any field in math

u are trying to find an error

by measuring a certain x close enough in f(x) u fill find a value close enough to said x

now u can say that continuity in topology is basically a function between metric spaces

i think most textbooks use a set of bases in metric spaces for the proof on topological continuity

but is practically the same intuition

also a lot of people find the neighbourhood to be more intuitive but i am not one of those people

[opal frigate]

hey!
if any german speakers here need help with Math, here is a Link to a site from a Fachhochschule (practical leaning University) in Vienna, Austria, which helps me quite a lot.
https://mathe.technikum-wien.at/
You can watch all kinds of explanations to fresh up things before the first semester (Basiswissen) and study up on things that you may or may not encounter during your studies (Studienwissen).
Here is where you find their videos, sorted by topic. https://mathe.technikum-wien.at/lernvideos Sadly it is a bit confusing in which sequence you should watch them, but mostly from top to bottom and left to right should serve you well.
There are also many, rather difficult test questions https://mathe.technikum-wien.at/index.php. You can sign up and track your progress, you can build your own tests and on top of that there are some scripts on there as well https://mathe.technikum-wien.at/gesamtskriptum.php. I have not checked them out yet, but they should be useful.

Sorry for my bad english, I hope this helps somebody as much as me!

[obsidian spire]

Its a function f that for any open set in the codomain has an open set 'source' (preimage of f) in the domain. And the closed sets have closed set 'sources'. At least that's how I usually think of it.

[rancid plaza]

i am sorry, i didn't mean to be disparaging

[steel plover]

hey guys, can someone help me out w part c?
the answer is supposed to be 5.82 (to 2dp)

from my understanding arg (z-a-bi) is the half line from the point (a, b), which in this case is (6, 0)? and the argument is the angle this half line makes w the real axis?

[raven galleon]

nw brother

[mystic thunder]

help

[obsidian spire]

Youre going to be more familiar with the specifics of these symbols/jargon. But the key comes from them being mutually perpendicular and what direction cosines are in R^3. Not sure what A' refers to to, but consider what a matrix getting multiplied on the right or left to I_3 signifies.

[little nexus]

It just comes down to properties of direction cosiness and mutually perpendicular

[mystic thunder]

yeah but is the second one a property? of direction cosiness , I can only recall the first one

the sum of squares = 1

[little nexus]

It's that for perpendicular vectors the dot product is zero

[mystic thunder]

Ohh yaaa Thankk you so much 🥰

[little nexus]

No worries. It was quite easy

[twin sinew]

@jade wave

[obsidian spire]

Guys.. I haven't used calculators or websites that graph things for awhile. I'm curious can they handle weird functions that have alternate formulas for say rational numbers vs irrational numbers? Would it draw two lines.. with the implication none of these lines have intersecting x-values even though they look 'connected' from a casual glance?

[sinful narwhal]

try checking the texas ti-nspire. from what I've heard, it's the best calculator when it comes to complex numbers and in terms of overall functionality