math-help

[mossy crane]

from assasination classroom

[deep kernel]

calc III ?

[icy spindle]

Yes

[mossy crane]

what chapter yall are at

[sly shadow]

do u mean differentiating it?

[icy spindle]

Integration on smooth manifolds

[deep kernel]

am doing calc II

[sly shadow]

its just intro calc 1 and algebra

[deep kernel]

but currently fasting my brain is on 10%

[mossy crane]

dam indian system just divides it explicitly

what does calc1 cover

[sly shadow]

we dont have calc 1

its just calculus then higher calculus

can anyone helkpo me im stuck

[mossy crane]

dam sorry just leaned how to differntiate like a week ago

[timid delta]

Oh

You are in HS?

12th grade?

[mossy crane]

ya

[timid delta]

Ohh

[bronze edge]

Wait what you guys get calc in 12th grade

[mossy crane]

wbu

i thought everyone does

[sly shadow]

i did calc in 11th grade

[bronze edge]

No, i'm learning by myself

[mossy crane]

based

[timid delta]

I did calc in 11th for physics , so I can say that too

[bronze edge]

Brazil is just built different lol

[mossy crane]

ya thats counterfeit math imo

[sly shadow]

but forgot it all cuz i didnt use it for my degree until i switched degree

3 years later

[icy spindle]

I did calc in grade 10 loll

[bronze edge]

LOL

[timid delta]

I was born while doing calc , jk

[icy spindle]

like derivatives and stuff only

[mossy crane]

3blue1 brown in 10th

[bronze edge]

I'm in limits, going to derivatives soon...

[mossy crane]

started learning calc without functions

struggled

so i dropped

[bronze edge]

Like i'm super late lol :' )

[sly shadow]

lol thats funny i was doing calc in my dads balls

[mossy crane]

how

we just finished limits last month

[timid delta]

But our maths teacher taught us like mid level calc( mid wrt hs)

[bronze edge]

I'm learning by myself, don't forget

[mossy crane]

based

[bronze edge]

I started some days ago actually

[timid delta]

Nais

[bronze edge]

so a lot of notes and everything

[mossy crane]

i can not learn math if someone teaches me

i can nver align my pace with the teacher's

[icy spindle]

edgy

[sly shadow]

is anyone able to help a brother out

[timid delta]

https://tenor.com/view/thats-totally-understandable-van-jones-big-think-i-get-it-understandable-gif-18731346

[icy spindle]

Is this all they gave you?

[timid delta]

Use Newton labneiz formula

[sharp ferry]

Eh? We had basic differentiation in class 11th?

[timid delta]

Aah wait

[sly shadow]

pretty much man

[icy spindle]

I dont think he is doing partial differentiation yet ahah

[bronze edge]

dude wtf you guys really have calc in highschool?

[icy spindle]

F(b)-F(a)

[sly shadow]

so the question before it told me to find the inverse then find f(14)^-1 using inspection

[icy spindle]

int a->b g(t) = G(a) - G(b)

[mossy crane]

basic maths for physics is counterfeit maths imo

[supple island]

isn't that -g(0)

rather than -0

[timid delta]

No

differentiation of o is there too

0*

[sharp ferry]

Yea limits and derivatives in grade 11 and integration and more about derivatives in grade 12

[timid delta]

So 0

[supple island]

yeah right i'm a dumbass

[timid delta]

Nah you are not , you know more than me XD

[supple island]

i mean i hope i do

[sharp ferry]

Nah we had differentiation in detail in math tho? Not in physics

[icy spindle]

Has anyone done a Group theory course here I have a question

[bronze edge]

Make the question, someone will awnser probably 🙂

[sharp ferry]

Did you take up pcm?

[sly shadow]

what theorem is that on the second line

[mossy crane]

y

[supple island]

you just integrate and then derive using derivative of compisite functions

[sharp ferry]

Coz u said basic math for physics but we had derivatives in math so I wanted to know if you took up math

[supple island]

btw if you guys ever need a good calc 1 book i can give you a link that definitely doesn't contain one

[mossy crane]

oh no i said yes but i am lazy so just wrote y

[sharp ferry]

Ah lol I thought u asked why

But did you not study calc then ? In physics we aren't taught first principle and stuff but in math we are taught all that stuff

[mossy crane]

11th
co-ordinate geo
trig
algebra
12th
calc
linear algebra

[timid delta]

Newton labneiz formula

Idk if spelling of labneiz is correct but it is something like this labneiz or lebneiz, Google it xD

[sly shadow]

ok i will study that

[supple island]

it's Leibniz

[timid delta]

Oh

[nocturne prism]

Both division and multiplication follow the same rule of
Same sign = positive
Different sign = negative

( -1 / -1 ) = 1
(-1 / 1 ) = -1
-1 * -1 = 1
-1 * 1 = -1

I guess that's the answer to ur question? Or that's what i understood xd

[sharp ferry]

Which syllabus?

[alpine mulch]

can someone help

i can send an exampl

-_- i plugged in "big" but idk what it implies

[supple island]

do you know what an asymptote is?

[alpine mulch]

yes

[supple island]

ok so what's the problem

the limit?

[alpine mulch]

find the asymptote by finding limits

for infinity and -infinity

[supple island]

ok cool

did you do the limts?

[alpine mulch]

lim x-> infinity=(big)^2 - 2e^(1/big) what does this mean

about the limit

[timid delta]

Damn I am seeing this type of question for the first time

[supple island]

big?

[timid delta]

Well ik how to solve it tho

I guess

[alpine mulch]

the damn example is like "plug in 'big'"

[supple island]

isn't this the problem?

[alpine mulch]

as in a large number

yea

[sharp ferry]

So doesn't this imply that 2e^(1/big) essentially becomes 0???

[alpine mulch]

o does it

[left knoll]

so is it ok if i put my question in here rn or shall i wait 💀

[alpine mulch]

🤔 o i see

ya go ahead

[timid delta]

You can

[sharp ferry]

Coz it's infinite root

[supple island]

ok so plugging in "big" is basically trying to do a substitution for the limit

[alpine mulch]

o so horizontal asymptote of 0

[supple island]

so if i say lim x->infinity x^2, im saying what happens if instead of x i put a really BIG number?

the answe is you get an even bigger number

[sharp ferry]

So it means one of em is x²???

[left knoll]

i believe 5a = 20.2, 5b = 1930cm/squared, 5c = 112m, idk what 5d is/ i think there's a 90 degree angle somewhere but i am confused. is the answer 90 degrees.?

[supple island]

so if i proceed to infinity, this limit is infinity

[sharp ferry]

Since 2e^(1/big) is essentially 0

[alpine mulch]

oh ok got it

[supple island]

nonononono

it's 2

[alpine mulch]

so y=0 asymptote how do i find other ones?

if there are

[timid delta]

Use sin rule for part a

e^(0)=1

[sharp ferry]

Howgshsgsh

[timid delta]

2×1= 2

[sharp ferry]

Yess

Okokok

Got it

Thanks nuke

[supple island]

ok so @alpine mulch you just have to do the limits for infinity are for -infinity for the given function

and then y=the solutions of the limits will be your horizontal asymptotes

can you explain me why?

[alpine mulch]

wat wait how do u do limit for -infinity_

-big?

[supple island]

very big negative number

[timid delta]

Would that line will be y= infinite? , Does that still have any signifance , a line horizontal at infinite? ( Am only asking for myself not contradicting anything)

[timid delta]

Very small negative number*

[supple island]

y=infinity is not an asymptote

[supple island]

yeah yeah

[timid delta]

Aah am sorry tho if I offend someone somehow ;-; ,( I don't wanna sound like rude guy)

[supple island]

np

you are right, it's a fine correction

btw in 20 mins when i'm done studying i can go on vocal if anyone needs anything

[left knoll]

Can anyone explain this? Ans for (i) is (-infinity, 2) and (ii) is [2, infinity)

[timid delta]

As x is greater than zero then x can assume any values between 0 to infinite , max value of function will be when x is close to 0 , and min will be when x tends to infinity

When it tends to 0 , function will tend to 2

And when infinity it will tend to -infinite

for part b

x²>=0

For any real number

So min will be when x²=0 and max will be when x²= infinite

[left knoll]

Umm I got the infinity part but I don't get why we've taken 2

In part a

[timid delta]

I have doubt from above questions , asymptodes are finite lines which touches the curve at infinite or -infinite , but in this question limit when x tends to infinite we get the limit of the function to be infinite and for -infinity it tends to infinite too ;-;

[timid delta]

Ummm you understand hindi right? #non-english-chat , hindi will be more comfortable and easy for me and you too ;-;

[left knoll]

Ohh haha ok

[supple island]

i'm done

[quaint imp]

thank u so much

[nocturne prism]

welcome :))

[quaint imp]

kk

[left knoll]

can you help me 😟

[supple island]

sec

i'm in chill and hang out channel cuz tutor rooms are too small

you can type here if you don't feel like talking

[left knoll]

5a = 20.2, 5b = 1930cm/squared, 5c = 112m, idk what 5d is/

Thanks @timid delta

[thorn adder]

Anyone help me with forming equations

I am so bad at that

[left knoll]

i did this so far

[left knoll]

& what year are you in ?

[thorn adder]

I am a class 8 kid

[left knoll]

what country

if u dont mind

[thorn adder]

I live in a foreign country

[left knoll]

💔💔💔 i dont even know where TB is😔

[thorn adder]

Where u from?

[left knoll]

scandinavia

[timid delta]

@supple island , uh triangle is on horizontal plane and TB is vertical so it would be 3D

[left knoll]

OHHH that looks right

damn 3d 😭

[west flint]

use trig for TB

imagine a pillar that is constructed on B

figure out AC

[left knoll]

wow

[west flint]

then BC

[left knoll]

yes thank youuu

[timid delta]

.

[west flint]

then use trig

[timid delta]

Oh so means answer would be horizontal asymptodes does not exist

Ty

[timid delta]

Send questions

I have 10 mins , before going to study

@left knoll

Send here

My dms are closed rn

Do you know about sine rule?

Of triangle?

a/sinA = b/SinB = c/sinC = 2R?

?

Ok

[left knoll]

guys does anybody know how to solve quadratic inequalities with letters in them?

[timid delta]

Now gtg

[left knoll]

pls

[timid delta]

Send question

[left knoll]

(a+3)x^2 -4ax>0

[timid delta]

Hmmm

[left knoll]

you know?

[timid delta]

Yep

coefficient of x² >0

And D<0

Solve this for a

[left knoll]

hey man do you know some online calculator for this typa thing?

with steps and all

[timid delta]

Uh wait lemme explain then

[vernal meteor]

hii

this is about exclusion-inclusion principle if anyone knows about it

[left knoll]

also what's the name of "a" in math language? english is not my first language

[timid delta]

a is the "a" +3

[left knoll]

yeah i know but what do you call "a"

[timid delta]

Singular thing?

Am not that good at English ;-;

#languages-help

[left knoll]

nah like coefficent

whatever xD

[timid delta]

So answer is in terms of "a" or just numbers?

Use snip , it's good for maths I guess

Phone app tho

[left knoll]

ill try

[timid delta]

But I never used any app before , but I have it on my phone , so it must be good xD

Did you understand my solution tho?

[left knoll]

hold on

can i send a picture of how i did it and then you tell me how to go on?

[timid delta]

Yeah sure

Aah my dms are closed ;-;

Send here

@supple island r u online?

[left knoll]

ight sending now

[timid delta]

Ok

[left knoll]

fuck it doesnt read does it

[timid delta]

Wait lemme send , if this helps then it's good

[left knoll]

don't look at the one on the top

[left knoll]

my book says this is the answer :/

[timid delta]

Yes , that's the answer

Uhhhhhhhhh

[left knoll]

:/

[timid delta]

How do I explain it tho

Am not good at explaining ;-;

[left knoll]

idk 😦

like how do i get theree 😦

[timid delta]

Which grade are you in?

[left knoll]

2nd year of high school

[timid delta]

Uh means 10th

Ok

[left knoll]

i guess

[timid delta]

Now wait, lemme write a detailed solution

[left knoll]

❤️

[supple island]

I'm online

[timid delta]

@supple island can you help marzio , I gotta go ,ty

[supple island]

Sure

[left knoll]

thanks

[left knoll]

omg thanks

[timid delta]

I have done it till here now

[left knoll]

you are so good

[timid delta]

@supple island he will continue , from where I left , ty

[left knoll]

tysm

[supple island]

We can go to #non-english-chat or in vocale if you want, i'm italian too

[timid delta]

@supple island Sorry to disturb you

[supple island]

@nuke sure!

Np

[left knoll]

lets go to non english chat

[sharp ferry]

I think I can help a bit but I'm not exactly sure xd

Basically in such questions you count the permutations by taking different objects at a time like taking math as one object taking is as one object and taking fun as one object and making cases where they repeat and stuff

For example when u take the permutations of math you already included the cases like (math) (is) xxx and (math)(fun) xx also the one case which is (math)(is)(fun)

And similarly in the permutations of is and fun so you can then just look at cases that are repeated and solve accordingly

[ancient agate]

how do you find sample mean when given population mean and standard deviation

[plush dew]

Sample mean = population mean

Sample sd = population sd / sqrRoot(size)

[sonic mango]

It’s Miu(N/(N+1))

[left knoll]

Would anyone like to help me on a math worksheet i have to do that is due at midnight for me (PST). Its Algebra 3 so a class before pre calculas. The worksheet is based on Trigonometry. Dm me if you have to time to help, its a short worksheet

[ancient agate]

tysm

[viscid hatch]

can someone help me with some algebra exercises?

[valid kite]

@viscid hatch Sure thing! What's the question?

[mellow bramble]

https://cdn.discordapp.com/attachments/840326295543873587/840348019157499934/unknown.png

[valid kite]

Are AC, AB, BC, AD, CD all line segments?

[mellow bramble]

there is a problem they are in spanish

but I can translate them for you

[past finch]

If tgθ = 2, then the value of cos2θ / 1 + sin2θ is:

someone can help?

[supple island]

can't u just do theta=arctg2 ?

[past finch]

yeah, but what to do next?

[mild night]

how do u calculate the volume of rectangular prism

[past finch]

Base Area x height i guess

[fringe narwhal]

Hi everyone can I ask for some help? 😓 I want to understand this inequality ''tactic"

How you know that y=0

And what means when x=1/2 or x=-3

[weary arrow]

y(1/2)=(2*1/2-1)(1/2+3) = (1-1)(1/2+3) = 0(1/2+3)=0

did that make sense?

[supple island]

sunstitute theta in os2θ / 1 + sin2θ

[fringe narwhal]

...😓no I'm so sorry

I continue with the explanation and was worst 😓😓

[weary arrow]

Ok, so you know that when you multiply something with zero, the whole expression becomes zero, right? Like 0*45 = 0

You do the same with the function, there are 2 factors (the parentheses), if one of the factors become zero, the whole function becomes zero

So the reason you make these parentheses, is to find what value of x makes the function zero.

You can test on the whole expression, if you set x=-3: y(-3)= 2*(-3)^2 +5*(-3) - 3 = 2*9 - 15 - 3 = 18 - 18 =0

[fringe narwhal]

Oooh okay, yes is more clear! Really thank you

Oh why did you put : between x=-3: y(-3)

[weary arrow]

oh it is to show an example where x=-3.

[barren venture]

Let

A = {all cases where “MATH” shows up}
B = {all cases where “IS” shows up}
C = {all cases where “FUN” shows up}

So for this question, it is easier to find | A u B u C | first. This thing means “how many permutations in which “MATH” and/or “IS” and/or “FUN” shows up”. If you imagine a Venn diagram, this is the same as finding all the cases in the entire Venn diagram.

Principle of inclusion-exclusion comes in here. By principle of inclusion-exclusion,

|A u B u C| = |A| + |B| + |C| - |A n B| - |B n C| - |C n A| + |A n B n C|

So now our job is to find everything on the right hand side. I’ll write down some of the stuff on the right hand side, see if you can see why and fill in the rest!

|A| = 6!
|B| = 8!
|C| = 7!
|A n B| = 5!

Once you get |A u B u C|, the answer you are looking for is

(Total number of permutations) - |A u B u C|

[fringe narwhal]

:0

I found what confused me

Why he change the 5x to -x+6x (how you know when do something like that?)

[weary arrow]

Oh, he just does this so that it is easier to make a fraction. As to how do you know when to do that? That's tricky, I guess you just have to think of doing it, it's not really always easy to come up with those things

You can use the classic (although a bit slower) method though: the quadratic formula

[fringe narwhal]

You are so kind 🥺💜 thanks!!

[sly shadow]

how do i do this?

[upper moth]

Does anyone know how to do this

[mental wraith]

Combinations are n!/(n-r)!r!, using that definition just solve the left side algebraicly to match the right side

[wooden dust]

does anyone know how to do this?

[mental dragon]

18 / (54-18) = FG / 16 <- solve for FG
The trick is using proportions. https://www.varsitytutors.com/hotmath/hotmath_help/topics/triangle-proportionality-theorem#:~:text=If a line parallel to,divides these two sides proportionally.

[surreal basin]

Hello I am to find the integral of (1-x²)^(3/2)/x² dx using trig sub , I used x=sinu but our teacher always neglect it and mark it wrong

It does not ask for the whole answer it just asks on the variable to substitute

Sorry for my English, not my 1st language

[left knoll]

@upper moth

[upper moth]

You saved me big time! Thank you!!

[left knoll]

@wooden dust

[surreal basin]

anyone

[icy spindle]

is it ((1-x^2)^(3/2))/x^2 or (1-x^2)^((3/2)/x^2)?

[surreal basin]

((1-x^2)^(3/2))/x^2

[icy spindle]

First start by integrating by parts, then you will find a neat substitution

you can break that big function into two smaller ones

[surreal basin]

yea but my question is that I always get to substitute x=sin theta

[icy spindle]

you shouldnt, sin theta doesnt apply everywhere

if you pick the wrong substitution youll end up complicating your life even more

you can call f = (1-x^2)^(3/2) and g' = 1/x^2

then use integration by parts, fg - int(f'g)

[left knoll]

does somebody know what is the angle of depression?

[surreal basin]

the lesson is trigonometric substitution tho

[icy spindle]

the angle between the line of sight and the line of sight down to an object

[icy spindle]

yes, but you have no way to substitute anything into the main function. Im not sure if you've done integration by parts, but thats the way to get the substitution in this case

[left knoll]

aaaah ty i am doing a test for my friend and i just saw that and didn't realize what that meant. Ty for help.

[timid delta]

Wut , ask him to do it , not you , how will he learn then?

[icy spindle]

lol

[surreal basin]

I performed integ by parts first

[left knoll]

ahh he doesnt rly care for school but he asked me for help and i wanna help him otherwise he will bully me

😦

[timid delta]

Whaaaa-

[left knoll]

yes little too complicated

[timid delta]

If he bullies you , are you sure he is your "friend" ?

[icy spindle]

you can use arctan u as a substitution instead of sin u

[left knoll]

mmm not rly

and angle of elevation is the same thing just from the bottom?

[timid delta]

Yep

If I were you , I would score minimum marks possible

[surreal basin]

okay bud thanks

[timid delta]

Negative If possible

[left knoll]

i mean its not possible rn but next time it can be

still this grades I get him doesn't matter, at the end of the final year there will be the test that includes every subject and that determinants if you can go to college

[timid delta]

@surreal basin I can solve without using integration by parts , do you want solution?

[timid delta]

All the best dude

[surreal basin]

Yes if its okay my friend

[timid delta]

Aah correction sin2u = 2x(√(1-x²))

[surreal basin]

Thank youuuuu

I already got it also using x=sinu but my teacher keeps telling me its wrong idek what to do ngl....I only got those

[timid delta]

Ohhhh

[surreal basin]

but anyways thanksss mate <333

[timid delta]

Well integration has many different approaches , you can only learn , its not any good in arguing with teacher ;-;

Np

[left knoll]

Does anybody know how to do this?

[timid delta]

1. it's a square

[paper talon]

1- (x-2b)2

2- [2x+'radical sign'3a)2

ıdk others

[timid delta]

Wait 5min

[mossy crane]

Avg pentonic enjoyer

Based

[timid delta]

I don't understand? What are you trying to say ?@mossy crane

[timid delta]

Try solving other parts like this

On your own

[left knoll]

jeez man thanks

i got it

[timid delta]

Answer for 1st will be x belongs to R

[idle moat]

whats e * e^x

[timid delta]

e^(x+1)

[idle moat]

thanks

[glacial robin]

How I can solve this de?

[unreal parcel]

hey can anyone please help me with thissinAcos2A=1/4sin4AsecA

this*

[full venture]

Halp part b ples

[unreal parcel]

nvm i got it sorry

[timid delta]

Hmmm

[timid delta]

Use a²-b²=(a-b)(a+b)

Use should get the asnwer from that

[full venture]

oh

im blind

[timid delta]

As a-b is constant, (1-2) , (3-4) ,(5-6)

Only remaining will be -1 ( 1+.........n-1) +n² ( if odd)

Now use AP summation

If n is even then -1( n(n+1)/2)

[odd grail]

how do you guys memorize the unit circle?

and i mean the radians

i know the first quadrant is pi/3, pi/6, and pi/4

[left knoll]

you dont need to memorize it

[odd grail]

really?

ive been lied to

ty

[left knoll]

i mean

you don't need to sit down and"cram" them. Once you start solving problems, you'll get familiar em' anyway.

[timid delta]

Yes

[odd grail]

gotcha gotcha

[viscid sand]

You don't need/have to

For the same reason you don't have to memorize the sine/cosine/tangent of all the possible angles

So long as you remember the major ones (Pi/2, 2Pi, 3Pi/2, Pi) and simple rule of three (Pi rad = 180º) you'll be good

[supple island]

you can always do Pi/180=x/θ

if you want the radiants

[viscid sand]

^

rule of three

[supple island]

oh didn't know it had a specific name

[viscid sand]

it's the name of the method, not the formula

[timid delta]

@supple island you are doing bsc physics right ? On which specific topic?

[supple island]

rn i'm preparing quantum mechanics

but in undergraduate we don't do anything too specific

[timid delta]

Ohhhh , so can you explain one thing? Why is the wave function of S orbital infinite at the nucleus , even tho there are no electrons in nucleus? ( I asked my frnd , he said because of its spherical shape ) , but it is kinda vague xD

[supple island]

one sec

[timid delta]

Although I know we calculate it by using probability density , but when I tried , the maths is above my level

So if you can explain in other way , that would help :)

[supple island]

isn't 0 at the nucleus and reaches its peek at the radius of the s orbital?

should be something like this

so for 1 s it's 0 at the nucleus

[timid delta]

Uh wait

Uh , pic became upside down

[supple island]

uh

what wave functions are those?

[timid delta]

For 1s and 2s orbitals

[supple island]

uuuuuh

i'm pretty sure what i've sent is the correct one

because the quadratic modul of the wave fnction is the density of probability to find a particle in a certain space

and the probability to find electrons attached to the nucleus is 0

[timid delta]

Hmmm

[supple island]

i mean, i guess it makes sense if you use the thomson model but that shit is old

we haven't used it since 1911

[timid delta]

Well I guess , this is true at HS level ;-; , no this is I guess for Bohr model kinda? , Aah leave xD

[supple island]

yeah bohr model is pretty much waht we use rn

if you want a good read on quantum mechanics, Feynmann and Sakurai-Napolitano are good books

but they use concepts that i don't think you've learned yet

[timid delta]

I will surely read that once I pass HS :)

[supple island]

😉

the introduction to quantum mechanics by Feynmann is great, it's simple and used by almost every professor

so you can read it and understand basic concepts pretty esaily

the maths

[safe helm]

looks like the squared radial wave functions, which are solutions of the Schrödinger equation for the coulomb potential

[supple island]

not so much

[supple island]

oh that makes more sense

[timid delta]

Yes it the solution of schõrdenier wave equation

But why it is tending to infinite when r tends to 0?

[supple island]

because

solutions of the Schrödinger equation for the coulomb potential
which is the elctric potential

i think nikomachts can explain it better than me

[floral marlin]

Hello, can somebody help me, I'm stuck on this problem: 2cosx*sinx+cosx=2sinx+1, I need to solve for x

[timid delta]

@floral marlin

[floral marlin]

Thank you very much!

[upper moth]

does anyone know how to do c) onwards

[safe helm]

according to the Schrödinger model, the electron could very well be very close to the core (since opposites attract in the coulomb potential, you have to solve the diff equation to find out), but can it really? you have to take into account the angular momentum (which should not be confused with the classic model one --> Heisenberg) --> Bohr model

you might also ask why the 3p electron for example cant hit the core, while the 1s can according to schrödinger?

thats because theelectron closer to the core is shielding the potential from the other electrpns

[timid delta]

Ohhhh

[cloud night]

Hello can somebody help me with q39?

[fickle mesa]

Hi, can someone please help me question 1

[supple island]

do you know the derivative of a composed function?

[cloud night]

ik but I need to find it with first principles

[supple island]

you mean with the limit of the difference quotient?

[cloud night]

yep

[supple island]

use prostapheresis formulas

[cloud night]

hmm I'll try, thanks anyways

[sharp ferry]

Ok so do you know what the double angle formulas are ?

[fickle mesa]

@sharp ferry yes

[heady tendon]

Does anyone have an idea for the function related to this graph ?

[sharp ferry]

Yes so in the first question it's more or less straightforward application of the formula cos²x=(cos2x+1)/2
sin²x=(1-cos2x)/2

[fickle mesa]

Okay, Thank you I am able to solve it now.

[magic ridge]

floor(x)/x

[faint thistle]

I got an artihmetic sequence question

The sum of the first six terms of the series is 7k+9

nvm

[faint thistle]

@timid delta Appreciate you bro

or sis idk

i already did it but still thank you alot

[quaint pendant]

No harm in being one

[frail marlin]

yup

[trim dove]

can someone help me with linear algebra?

[coral dove]

im really confused on this probability concept. i was wondering if someone was willing to watch a part of my lecture and explain it to me?

[weak silo]

my major is engineering, but i'm planning on taking physics as a post degree

[weak silo]

pythagoras theorem, (9/10)² = b² + (2/5)²

[left knoll]

i did that and i got 81/100

[weak silo]

exactly, now you have 81/100 = b² + 4/25

we find a commom factor to 100, 1 and 25 so everyone can have the same denominator

you see, 100 is 25 times 4 and 1 times 100

4 and 100 are the factors, multiply b² by 100 and 4 by 4

[left knoll]

so 16

81-16

65

[weak silo]

yup, b² = 65/100

[left knoll]

ohh

y!

ty!*

[warm mesa]

i have to use the binomial theorem?

[steady tide]

Yes

You can also use Pascal's triangle

[warm mesa]

ty!

[random flame]

Eyo is it okay if someone can help me with Q1b? Ping if you do and thanks in advance!

[left knoll]

16.609@random flame

[random flame]

How did you get the ans?

I tried making the equation into 100 000 = 2^t first

Not sure what to do next

[royal finch]

The first step u did is correct

just take log to the base 2 on both sides

and you'll get t = 16.609

[random flame]

Can I use ln btw?

[royal finch]

someone helf

[royal finch]

nah dude, ln means the base in e. You've gotta use log to the base 2

[random flame]

Ah k thanks man

[royal finch]

np np

[loud nymph]

Can someone help me? You have to describe the Taylor-series of these functions and xˇ0=0.

[bronze bison]

use app

Photomath

on android

[plush grotto]

can smbdy pls explain this to me

[sharp ferry]

Okay so do you what are the requirements for log base b of a to be defined in the realm of real numbers?

[zenith torrent]

need help with math

In a triangle ABC , AB = x - 5, BC - 2x+1 and <ABC = 90 degrees. The area of the triangle is 69. Find x

[left knoll]

The answer is 11

The method is

Area of triangle ABC =1/2 × height ×base

=1/2×(X-5)×(2X+1)

=69

1/2×2X^2-10X+X-5=69

2X^2-9X-5 =69×2

2X^2-9X -5 =138

2X^2-9×-143

=0

( by Splitting the middle term)

2X^2 -22X +13X -143 =0

2X (X-11) +13( X-11)

(2X +13) ×(X-11)

(So either 2X +13 =0 or X-11 =0 )

If 2X-13 =0 then

X=-13/2

If we put this in AB

It becomes = -13/2 -5

=-23/2

This is false as distance can not be in negative terms

So that means

X-11 =0

X=11

[left knoll]

Did you get it ?

[zenith torrent]

thank you, and yes i do get it Ive been stuck on this for ages'

[left knoll]

Ok

[barren venture]

So first observation is that x can only take values from 1 to 5. This is because if x = 6, then y is at least 7, and z is at least 8, so the sum is at least 21, which is greater than 20 already.

Now you just need to check each x from 1 to 5 individually. I’ll do the case for x = 1 as an example:

x = 1 means we want to find all (y,z) such that y+z = 19. Also remember that y is at least 2 (since x is 1) and y < z. This gives us the combinations (2,17), (3,16), ... , (9,10). So x = 1 gives us 8 possibilities.

Repeat this for x from 2 to 5.

[royal finch]

damn

it'll take time i guess

thanks 😄

[barren venture]

Not too much time, because the numbers are still small 🙂

The largest case is the one I’ve written out, and it’s only gives 8 possibilities

[royal finch]

ouu

themks

[smoky creek]

Hey

Does anybody know about trignometrical identities?

I need help with that

[pallid notch]

I don't know if i can solve that, but can I ask?

[smoky creek]

K

1. (Cosec)4 A - (Cosec)2 A = (Cot)4 A + (Cot)2 A

2. Sec A (1 - sin A) (sec A + Tan A) = 1

q: prove that LHS = RHS

@pallid notch

[pallid notch]

Thank you! I'll try

[smoky creek]

Thanks

[smoky creek]

Uhh hello? @pallid notch

You there?

[pallid notch]

@smoky creek

[smoky creek]

Oh thank you

So

LHS = RHS

You took the RHS too

Wow that was a great idea @pallid notch

[pallid notch]

@smoky creek

1 other

@smoky creek ok?

[glossy falcon]

for some reason am stuggling with this one

can anyone help me

need to find the roots

[weary zodiac]

there's only one root

[slate dune]

to find roots just make f(x) = 0 since f(x) is y

@glossy falcon

[glossy falcon]

yeah but when i try solving it i get stuck

[slate dune]

Are you allowed to use a calculator?

if u can you can graph it instead

[fading crest]

oooo ill try

[glossy falcon]

no solve it without graphing it

solve it by hand

[left knoll]

use newton's method lol

[left knoll]

well, find the first root by trials and errors and then divide f(x) by that factor to get the other 2 roots

[latent siren]

You can kind of cheat by knowing what the roots are.

Its roots (are) x=1/3 with multiplicity three.

[glossy falcon]

the answer is supposed to be 1/2

[latent siren]

ah yeah, 1/2

So you can factor it out by (x-(1/2))^3

[glossy falcon]

oof am gonna skip this one and vome back for it later

[latent siren]

(x-(1/2))^3=0 is the same as 8x^3-12x^2+6x-1=0

[glossy falcon]

ooh

yeah i will try this one after a bit

thanks for your help guys

[left knoll]

Can someone help me to get over my anxiety of maths?

I know I can do it but deep down I'm kinda afraid of maths

[pallid notch]

@left knoll of course!!

If there's anything I can do.

[icy spindle]

Practice; once you get 'used' to seeing weird, hard and complex things, your brain won't go all berserk.

[left knoll]

Hello

Does someone know a good website / book to explain graph in math

For example linear

[left knoll]

WolframAlpha, Desmos maybe.(not sure what you mean by "Explain graph")

[left knoll]

Like how to understand stuff like this

[left knoll]

The thing is that I do great in practice

but when I see the paper my Brain.exe stops working

[left knoll]

What do you not understand in this?

Also I do soooo many elementary grade mistakes

like misplacing decimal points

Addition mistakes

subtraction mistakes

and the sorts

Well I am cornered I suppose

I'm gonna fight my way out

2 hr Maths session here I come

[left knoll]

I’m in grade 11 and I forgot everything about graphing because I was all in algebra and geometry 😣😣

[left knoll]

Afaik you learn Calculus in high school, that will help you a lot with all this.

But I don't know of any sites that teach about Graphs and stuff.

[pallid notch]

@left knoll
Believe in your own practice.
Do the math carefully.
Solve twice.
I used ballpoint pens for studying and saved them after I was done with them.
The more ball-point pens I kept, the more confident I became in knowing how much I had studied.

[left knoll]

Thanks for the kind words

[left knoll]

trust the process I got it

[dusk stone]

HELP PLS

[pallid notch]

My first thought was partial fraction decomposition

[unreal rampart]

I believe you need 4 food N and 2 food M since 4 * 1+2 * 2 = 8 and 4 * 2 + 2* 1 = 10

[dusk stone]

Thanks

[near verge]

yeah mb sorry sdjkasdjd

[sharp ferry]

You can use the depressed cubic method but it's kinda complicated

If you cannot guess and check this method is the hard but definitive way

[left knoll]

Does anyone know how to do this?

[sharp ferry]

Like you don't need to guess and check you just have a solution

[sharp ferry]

Can you send an image?

[left knoll]

sure

It is the study of each function with every calculation and the graphic

the titles are in spanish but never mind

which year are you in?

[sharp ferry]

I have no idea maybe @supple island can help

[sharp ferry]

What do we have to solve here I just see a bunch of functions

[left knoll]

well each function

[dawn kindle]

can someone help me please,its about conditional probability

[left knoll]

well, the only thing i want to transmit is that Spain has a bad education system, the only thing they do is send us homework to do and make us study 300 pages of history, language and 13 chapters of physics and chemistry, and another 13 chapters of mathematics for an exam which will decide our future

Would anyone like to help me on a math worksheet i have to do that is due at midnight for me (PST). Its Algebra 3 so a class before pre calculas. The worksheet is based on Trigonometry. Dm me if you have to time to help, its a short worksheet

Im in the 11th grade as well.

Can someone tell me the answer? I feel as if my answer is correct

[timid delta]

Uhhh

[timid delta]

We have to find domain and range ? Or what? Like what is the question?

[timid delta]

All are correct for this

[bleak forum]

Check this approach!😅

[timid delta]

Number of elements in power of a set is 2^n

[left knoll]

WTF

The official answer key says answer is C

[timid delta]

A set is a subset of itself

[left knoll]

it's from UPSC

[timid delta]

Well I think In option 2 is talking about proper subset?, But every set is a subset of itself

[left knoll]

illuminati music plays

SO the answer key is wrong?

[left knoll]

could be, yes

[timid delta]

If it's talkin' about proper subset then it makes sense

[left knoll]

I find it hard to believe that the UPSC is wrong

[timid delta]

If it's from UPSC. Then obvio you can find solution on net right?

[left knoll]

It's the official answer key

On the UPSC webpage

Anyways no point in wasting time over this

I wonder why there's no talk of this online

Anyhow

Thanks for being patient with me and helping me out

[timid delta]

Np

[ruby tinsel]

I don't know if this advice would help, but when you physically graph it, you can actually understand it?? Maybe make a table of x and y for each function (ie. y=x^3, y = |x|...) and plug the numbers in and graph then to see how they look like.

[supple island]

Is my help still needed?

[left knoll]

If you really want to graph functions without plotting outputs at different inputs, you need to know Calculus. If you are good at Calculus then graphing Functions isn't a difficult job.

[kind grove]

still need solution?

[glossy falcon]

yea...

@kind grove

[kind grove]

U know synthetic division?

@glossy falcon

not sure if thats a method that your prof accepts, but it works

[glossy falcon]

Thanks for your help

[timid delta]

I did this , after that you can solve it for 't'

Solve for t

In first pic I actually wrote p(A)= 0.6 becuz i thought p(A') was 0.4

[zenith citrus]

Anyone know how to write the following function in an equivalent form that does not have any trig functions? Am pretty stuck

[timid delta]

Let me resolve the question in more clear manner

[supple island]

everywhere or only in a certain neighbourhood?

[zenith citrus]

everywhere unless that doesn't seem possible

[supple island]

so you have to write a periodical non trig function?

uh

[pallid notch]

If we could delete tan^2(x), there would be no trigonometric functions.
We might be able to use substitution integrals.
I'm sorry I can't help you.

@zenith citrus

[supple island]

hm, you forgot the derivative of tan x

[kind grove]

then rewrite tanx as a maclaurin series maybe?

[supple island]

there's no limit

it's not like it's approching 0

so you can't do that

also you still gotta put 1/cos^2x in that integral

[kind grove]

we need limits for that?

[supple island]

yes, Taylor series are approximation of a function in a certain point

Mclauirn is specifically when x->0

[kind grove]

true, but we know tanx is continuous except for the asymptotes so it would still work right?

[supple island]

no because the taylor series of tanx in 0 and tan x in 2 are def not the same thing

[kind grove]

true so between -1 and 1 could work

[supple island]

still no, because they would be different

again

taylor series are for when a function approaches a specific point

[kind grove]

sorry not -1 and 1 but pi/2 and -pi/2

[supple island]

so in a very close neighbourhood of that point

(-1,1) is not a very close neighbourhood

[kind grove]

so what would be the answer to the original question

[supple island]

still thinking about it, idk if i can solve it, maybe there's a very smart and easy solution/method that i'm not aware of

[supple island]

also note that this method is NOT correct

saying that a function is the primitive of its derivative is not correct

because when you derive you lose constants

and when you integrate you have a +C that you have yet to define

it's ok if you define the extremes of the integral

that's why integral functions have the extremes from a point to x, in this case the point might be 0, because it just means that at 0 the integral function=0

is this supposed to be an equation?

[tame frost]

Yeah

[supple island]

well, what's on the right then?

[tame frost]

I meant if anyone knew how to do the question

[kind grove]

doing the order of operations?

[supple island]

yeah i mean, equations usually have a left and a right hand side

[left knoll]

Is there any term on the right side? since we're solving for x

[tame frost]

Your suppose to find the answer

There’s nothing on the right

[supple island]

oh

[left knoll]

ohk

[supple island]

then just do operations in order i guess

[left knoll]

yep

BODMAS

[supple island]

following the order of the parentheses

[kind grove]

multiply 3 by (x-2) would be the first step @tame frost

[coral sierra]

not sure how to actually finish it off

haven't touched trig in a while, but I hope this leads you somewhere useful
Just sort of played about with the triangles u get from it and ended up with a trapezium, maybe manipulating that a bit more might end up giving the answer. Would love to hear how you solved it if you end up figuring it out

[tame frost]

Got the answer

[peak pollen]

Can anyone help me on understanding some math i got to remember for my Mocks?

I can't seem to remember half of the things i learnt a year ago

[spare bough]

You'll need to redo the classes from your notebook, i think that's the easiest way to remember everything, that's how I do it.

[peak pollen]

Yeah i know but I didn't keep my notebook from last year (which was my fauly)

[spare bough]

You could maybe borrow from some of your classmates?

And tell them like you'll return it in a week.

[peak pollen]

In Qatar everyone is about money

I'll just find a good website with math info it will just be more time taking

[spare bough]

eh I'd help if i knew high school math but i'm not good with it even at 9th grade :(

[supple island]

what were the subjects?

[peak pollen]

You don't mind if i DM the Topic list?

[peak pollen]

It's okey 🙂

[supple island]

sure, maybe i can find a good book about them

[left knoll]

hey guys

[low dome]

hi

[bleak forum]

try using complex exponentials, but it will make the equation quite complex

[kind grove]

I found k=2 and k=pi*n/x

but i dont think the pi*n/x is right. Can someone help?

[latent siren]

You forgot k=-2

[ancient agate]

i have standard deviation and mean, how do i find the chance that x is in the 95% percentile

[latent siren]

For what values of k is sin(kt)=0?

sin(kt)=0 if and only if kt=npi. Solving for k gives you k=npi/t (for integer values of n).

[kind grove]

yes but the problem is webwork does nto recognize the n

so im like bruh

[mental dragon]

Is there more to the problem?
I think, by definition, a randomly chosen number x from a distribution has a 5% chance of being in the 95% percentile of that distribution.

[ancient agate]

the question is: "x is the 95 percentile score"

[mental dragon]

sorry to be pedantic - I think I still don't understand the question

Assuming IQ scores are a continuous distribution, there isn't really a way to determine the probability that a random number is exactly the 95th percentile score (that would be like asking: what is the probability that it's exactly 40.0 degrees outside?)

Do you think the question is asking whether x is within the 95th percentile? Or something else?

[peak pulsar]

Is there anyone who has taken The SAT but not a native English speaker ? I need some advive 😉

[mental dragon]

If the question is "probability that x is within 95th percentile", and x is a random number from the distribution, I think the answer is still 5% (doesn't depend on mean or standard deviation) 🤔

the x-intercept is the point on the line where the y-value is 0. To get the x-value of the x-intercept, you plug in 0 for y and solve for x
(and vice versa for the y-intercept).

[random flame]

Eyo I need help with this question. Ping if you do and thanks in advance!

[drowsy oriole]

Why x=1?

[left knoll]

the function has an absolute minima at x = 2a

and the output at this input is -8

(2a)^2 - 4a(2a) = -8

solve for a to get your ans

[random flame]

Why tho?

[left knoll]

critical values(Minima and Maxima) occur where the derivative of the function is 0

f'(x) = 0 at minima and maxima

[drowsy oriole]

You can know what are the values of x when f(x)=0 (x=0 and x=2a)... The half of the distance between those point on the plane will help you know what is the cordenate x of the vertex of the parabola (because of the simmetry of the parabola) and also you know the cordenate y of the vertex because the range is >=-8. From here you can remplace the values of y and x and find a.

[drowsy oriole]

From the point of view of @left knoll , you can derivate the function and make a system of 2 equations where the first one is (2x-4a=0)->(f'(x)=0) and (-8=x^(2)-4ax )

[last pagoda]

help pls

[left knoll]

help please

[drowsy oriole]

d/dx [ln( f(x) )] = [1/f(x)]*f'(x) . here f(x)=ln(e^(x^2))

[surreal basin]

Yow am I right with this one?

[rustic sapphire]

need help

[drowsy oriole]

On the part : 3x+4=A(x^(2)-x-1)... it should be A(x^(2)-x-2)....

[rustic sapphire]

S.T means show that

[surreal basin]

Oww my bad thanks bud

[drowsy oriole]

Then A=-1, B=4/3, C=-1/3 (just checked with a program)

[surreal basin]

Thanks bud how bout this one buddy, I got 1,-1 and -3 but not sure

[quick dome]

Can anyone help with this one? It's really tough for me

[clever orchid]

[1/ln(e^{x^2})]<>[1/e^(x^2)]<>[e^(x^2)]<>(2x)

I have used <> to represent multiplication instead of * because the asterix was just making the text italic

[knotty nexus]

hello! does anyone know how to do optimization and related rates? 😭

[left knoll]

You should have a good understanding of Derivatives.(+ Minima , Maxima, Inflection points and all that stuff).

[left knoll]

Are you writing an exam/ test?

[knotty nexus]

i do understand derivatives, i think i'm just confused on how to do the actual solving and stuff

[surreal basin]

ye suresure

[knotty nexus]

thank you! could you help me on this problem?

[golden nebula]

Volume = h*x^2 and surface area is x^2+4xh = 1200

change the surface area equation with subject h and then plug in volume equation

then use derivative to find extrema, finally just proof extrema is maxima

[knotty nexus]

thank you so much! <33

[zinc dagger]

does anyone understand what boundary points or boundary is

mvc

I don't understand the intuition behind boundary points
or boundary
So let A = {(x,y) belong to R^2 | x >0 }, then it states that the boundary of A is the y axis
is it because it can't go to the negative x side
meaning that the y axis is being the "boundary"
so if A was perhaps changed to y = 0
would that mean the boundary is the x axis
since y has to be equal to 0 or be on the x axis

[golden nebula]

u mean A = {(x,y) ∈ R^2 | y=0 }?

[zinc dagger]

for second scenario

yea

A is an open disc

so I'm guessing if it was like y > 0

then the boundary would be the x axis as well

likewise for y = 0

[golden nebula]

i'm not sure for y=0 whether x axis is the boundary because A also include x axis?

[zinc dagger]

ya

[golden nebula]

it is the set of points in the closure of S not belonging to the interior of S.

from wiki

[zinc dagger]

hm

okay

ty

lol

ill ask in oh

[knotty nexus]

would the answer here be V = 4000? i'm not sure if i did it correctly,,

[rustic sapphire]

anyone here to help me with applicaations of derivatives

[latent siren]

The way I think about boundary points of a set, say A, is that it is the set of all points such that if you take any neighborhood at any of its arbitrary points, that neighborhood will always intersect points inside A and outside A. So in your example A = {(x,y) in R^2: x>0 } the y-axis is clearly the boundary point because any open disk of a point in the y-axis will include points both in and outside A.

[rustic sapphire]

please

[latent siren]

.

[zinc dagger]

so if it was say y= 0

then that means x axis would be the boundary right

since it would have points outside and inside

the neighborhood of the x points

[latent siren]

You mean the line?

[zinc dagger]

yea

[latent siren]

Yeah, that's the weird thing about some sets, it can be its own boundary set.

[zinc dagger]

there can be also situations without boundaries right

[latent siren]

Sure

[zinc dagger]

tyty

[latent siren]

R^2 does not have a boundary

[golden nebula]

yup

[latent siren]

Ah, but this actually depends on the topology.

[latent siren]

Only A and C I think. B is not differentiable at x=0, and D has a discontinuity at x=1

[rustic sapphire]

ok thanks bro

[latent siren]

El Psy Congroo

[rustic sapphire]

El psy congroo

🤟

[latent siren]

Good luck you mad scientist. Calculus is important, study well.

[latent siren]

Woops, there a problem in C bro! It's not continuous inside the closed interval [-pi/2, pi/2]

It's not even defined in the endpoints.

[azure acorn]

https://cdn.discordapp.com/attachments/835908339631259678/841195218690244648/unknown.png

https://cdn.discordapp.com/attachments/835908339631259678/841195065305333790/unknown.png

[twilit locust]

hey guys. do you mind helping me with this problem about related rates? thanks in advance!

[azure acorn]

Dr/dt = 7

Volume of sphere = 4/3pi r^3

Differentiate

DV/dt = 4/3pi 3r^2 dr/dt

[twilit locust]

noted. thank you!

[upper moth]

I forgot how to solve for these types of problems. Can anyone help me out

[golden nebula]

L'Hopital?

[left knoll]

yeap

[surreal basin]

FIND THE DERIVATIVE OF THE NUMERATOR AND DENOMINATOR

THEN PLUG THE LIMIT

[timid delta]

Np

[sly shadow]

hi can someone help me with polar plotting

[supple island]

do the sum of angles for the triangle ADB to find the angle ADB and ADC, then do a system with the sums of angles for the triangles BAC and ADC

[latent siren]

I have never seen this notation before. What does H mean?

[tame helm]

I think you don't have to know that to solve this problem. i don't know the answer though🤪

[sly shadow]

r=H(theta)

[west plinth]

what is a good way to study for a math test I have one tmrw and i dont think im ready and im bad at math

[tame helm]

then the answer is the second one H((theta-3/pi)- pi). rotate 180 degrees.
check this https://math.stackexchange.com/questions/154743/how-to-rotate-a-polar-equation

[silk quiver]

x=30

[sly shadow]

NO SORRY R=1/2h(THETA-PI/3)

[tame helm]

right but it doesnt matter. what matters is this form H(something - pi) .

[full quiver]

can someone help me to know how to graph this? pls pls

[timid delta]

Hmmm

Divide by √2

Wait lemme write

Now plot the graph , by using transformation :)

[full quiver]

OOOO THANK U SO MUCH ^^

[timid delta]

It would be like this, its just a rough graph tho

[timid delta]

Np

[full quiver]

i got it, i got it thank u 🥺

[latent siren]

Don't study a day before the exam.

Do problems everyday.

[west plinth]

ok i did some problems already

but it is tmrw

so what should i do now?

[timid delta]

Maximum you can do is revise theory and formulas

[green field]

hi, I need to find the Dirichlet density of the set of primes where "p+1" and "p+2" are squares mod p

help please... 😦

[weak silo]

"find alpha and beta such that both lines are on the same plane, then find the general equation for their plane"

i'm not really getting, they need to be linearly dependent to be on the same plane?

[timid delta]

Coplanar vectors are linearly dependent

[left knoll]

how are you guys with probability ?

it's such a long q-

[timid delta]

Send ques , someone will solve it :)

[left knoll]

okok thanks

[dense wadi]

How can I get better at logarithms, it is the one topic i seem to not understand :*(

[left knoll]

im really only on part e

[timid delta]

Well yes someone will , am too lazy to solve it now xD

And idk if I will be able to ;-;

[left knoll]

it's alright bro

[dense wadi]

lemme try solve Nin

[left knoll]

is it a specific question or just overall ?

[dense wadi]

overall

[left knoll]

damnn i see

im gonna finish my stuff first & then i'll come back-

[timid delta]

1-22/110 e part 1

[left knoll]

but u should try to check out youtube for the mean time -

[timid delta]

110-22/110

E part 1

[left knoll]

i see . 😭 thanks 100% i think im starting to understand it

[timid delta]

Part 2 is conditional

Like

Uh not that type well leavexD

Only e 2 and e3 I can solve

I forgot statistics ,so I don't know other parts

K._vn. will help