#math-help

1 messages · Page 8 of 1

trim saddle
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Two posts with 5m of height are separated by 5m. There is a cable conecting both posts on their tops. The cable is 10m long. Whats the minimum height betwen the cable and the ground??

weak lotus
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This is a really fun one actually

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Let me show you

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Have seen hyperbolic functions

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You could graph it and use hyperbolic functions

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X-axis should be -2.5 and 2.5 my bad

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Hope this gets you on the right path, good luck

weak lotus
trim saddle
# weak lotus

i dont know how to continue. should find the minimum of the function by derivating it? whats the function? or should i go by a triangle and find the angles/sides?

weak lotus
#

If you the function you derive it to find a min or max

trim saddle
#

<@&942391219206647828>

trim saddle
weak lotus
#

Oh you havent seen those functions yet?

trim saddle
weak lotus
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Oooo

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Yeah then its to do with hyperbolic functions

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Idk if you have the solution? You can check if you want

gray veldt
#

@trim saddle is the answer is 0.88 or 1 ?

trim saddle
gray veldt
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Soo, when will you get the key? @trim saddle

weak lotus
#

im sure there are different ways on how to approach the problem

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i just thought hyperbolic functions were the best approach (imo) but sure you can solve differently

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maybe even trig functions

gray veldt
#

1812_wutcat trig aint useful here

trim saddle
#

chatgpt solved with a simple Pitágoras theorem, but i think its wrong

gray veldt
weak lotus
#

you could rescale everything so they are part of the domain

trim saddle
weak lotus
gray veldt
gray veldt
gray veldt
weak lotus
#

we got it so thats the most important part!

gray veldt
#

YEah!!

trim saddle
#

guys, off topic question, will james stream again?

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its been a while

gray veldt
#

dunno man :(

weak lotus
# trim saddle but yeah gpt said close to .88 too

i dont know if you are seeing derivatives etc but i can give you a tip: if you are asked to find a min or max of like a volume or surface,...
you can (always) like most of the time, solve those kind of problems with graphing it with x and y coordinates

gray veldt
#

Well one of this type was asked during the interviews conducted by amazon

weak lotus
#

thats sick yo

trim saddle
#

cs stuff?

gray veldt
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yeah cs stuff

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it wasnt this hard, but a logical question which can be answered in seconds if you really use your brain

weak lotus
#

and dont overthink the question xp

trim saddle
#

ye they do that

weak lotus
#

cuz stress can do mad stuff

gray veldt
#

@trim saddle ayo le me know if you get the real answer(key)

trim saddle
gray veldt
trim saddle
#

man i did memorized it. i was searching and found it. sorry i dont have the answer

gray veldt
#

Well I was appreciating your memory power nvm

trim saddle
#

i shared with you bc i didnt have the answer too ehehe

lusty hare
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Hi guys

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How would you have solved this system with four unknowns and what parameters would you have chosen to change the variables?

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thanks for the help

left knoll
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This is how I would have done it, which is very similar to your solution.

lusty hare
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Thank u so much

fiery widget
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Hi how would you do b)?

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I dont think my answer is correct, as for fg(x) i got (x+3)^2+2

gray veldt
fiery widget
gray veldt
solar drift
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can anyone please solve this? ig i am doing calculation mistake

weak lotus
#

<@&942391219206647828>

frank igloo
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Hi, does anyone know what formula to use to solve the cross product of two vectors that both have two points in a 3d space? All I can find is how to calculate for vectors which have one point. Or do I somehow choose which one of those points to input in the formula?

fiery widget
meager kite
#

cross products are normally just done with the vector components

frank igloo
# meager kite cross products are normally just done with the vector components

well i'm asking because i'm doing a thing for programming, and the task we're given has you create a vector "with two points" so each vector has such coordinates stored in an array - x1, y1, z1, x2, y2 and z2. One of the functions i need to implement is a crossproduct of two vectors. I think I understand how to do it normally, but this "two points" part is messing with my understanding

frank igloo
#

Anyway, I think I'm on the right path, i think the description our prof gave us "vector with 2 points" is instead meant to be a line segment. And then I would need to get the vector from that, and then calculate the cross product. Does that make sense or am I still doing something wrong? If it does, then I've solved the mystery, otherwise someone tell me I'm tripping

compact needle
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hey guys, can't figure out how to form the equations for this problem, i get decimals with mine 😭

compact needle
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i didn't get how to make the equations though

compact needle
compact needle
compact needle
obtuse lagoon
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can someone help with this co-ord geometry question pls🙏

maiden epoch
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Why we’re taking [1/2;inf) as an answer?

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@weak lotus sorry for disturbing you, but maybe you can explain?

weak lotus
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2 says x has to be larger then 0,5

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or equal to 0,5

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everything larger then and equal to 0,5 = 0,51,0,52,...n

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with n = infinity

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@maiden epoch

maiden epoch
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so why we wont include -1?

weak lotus
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because zero is always larger then -1

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and

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you need all solutions

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i think you can have nr 4 to

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-x >= x +1

maiden epoch
weak lotus
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number 1 is false as you did above
number 2 is x being larger and equal to 1/2 so till positive infinity

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BUT

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0 is always bigger then -1 and 0 isnt a variable its a constant

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you need to know the values of x which is a variable and thats for (1/2; + infinity(

maiden epoch
#

interval ends on -5/6 because it must be bigger then x? or?

weak lotus
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do not include -5/6

gray veldt
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Well its the real method, If you want it

dense wigeon
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How do i solve this

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I'm stuck here

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I tried various things, like substitution

naive dagger
#

I don't understand this formula:< can someone help me with it

left knoll
#

hii, can someone explain this to me? im watching a class video on how to solve it but i just don't get it

unborn creek
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for b

gray veldt
fringe trellis
#

hi does anyone know how to solve this?

night kindle
#

Can someone help me! My teacher teach me Dijkstra's algorithm, and this is a example about it. I just don't know how my teacher write this table and how it work?

copper forum
cunning oasis
#

Hello can someone help me in the last equation why the right hand side is one?

cunning oasis
#

book= fundamentals of wave phenomena, akira hiroshi page 149

obtuse lagoon
cosmic kestrel
fringe trellis
cunning oasis
cunning oasis
left knoll
#

Anybody studies math in french?

warped panther
slim prawn
#

Anyone can solve this question?

gray veldt
obtuse lagoon
#

can someone help w this differentiation and integration q pls 😭

obtuse lagoon
#

both if u could 🙏

gray veldt
obtuse lagoon
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yes ! much appreciated

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this is the answer

gray veldt
obtuse lagoon
#

THANK YOU SO MUCHH !!🙏

unique coral
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the last

gray veldt
#

if it is a square then the answer would be around 44.5

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use Cos(90-theta) = Sin(theta), you will get 44 pairs of(sin^2(theta)+cos^2(theta)) and a lone term sin^2(45)

slim prawn
gray veldt
#

Tbh, you can take any point on the circle in the given equation and substitute in arc sinx and siny

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pick (1,0) xD

fiery dome
#

Probability calculations:
P(B|¬A) = 1 - P(¬B|¬A)
Is this correct?

slim prawn
quartz epoch
#

i need quick help

sharp ferry
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the max value of arcsin corresponds to max value of y and min to min value of y then u have the range

timid delta
vale wyvern
sharp ferry
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as they say.Give a man a fish, and you feed him for a day. Teach a man to fish, and you feed him for a lifetime

fiery widget
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Hi can someone help with me part a)?

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I use u = 3+2x

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but the worked solution gives me this as the method on how to complete

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I understand the concept of where the u-3 and the 2dx being replaced by du

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but I dont understand why it becomes over 4

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any help would be appreciated 🙂

sharp ferry
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the 2s get multiplied

fiery widget
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im so stupid thank you so much

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I got so confused by the mark scheme saying 2dx = du

fiery widget
sharp ferry
fiery widget
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What about this one?

spare ice
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help please 😭

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NVM guys I solved it 👍

sharp ferry
# fiery widget

put x=sinu then dx=cosudu then it will be sin^2u * cos^2u du = (sin2u)^2 du then you can just turn it into cos4u

still radish
#

Hey everyone hope you're doing good. I'm studying Statistics and Probability in Maths if someone can help me with resumes or courses about Probabilty. Thanks 😁

still radish
weak lotus
#

Let me share you a link because my native language is dutch

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Khanacademy is really good to

cedar badger
#

Please help

gray veldt
#

Language?

neon shuttle
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How should i become fast

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in math

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i was called im slow at math

gray veldt
weak lotus
# neon shuttle How should i become fast

Practice makes perfect. Start from the bottom. Make sure your fundamentals are ON POINT. make A LOT of practice problems. The more you do, the more you learn, the goal here is to connect neurons and the more neurons arz connected, the faster you think!

left knoll
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Anyone explain it plz

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Check for injectivity part ..

still condor
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all the points that can be represented on a graph denote a real number, right?

gray veldt
still condor
gray veldt
atomic dagger
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Hi, I'd like help with a very simple problem...

A DVD production cost is 25 euros. When the factory sells one unit to a store, it makes a profit of 40%. What must be the selling price of the DVD so that the store makes a profit of 30% ?

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i completely forgot how to do something like this 1812_wutcat

atomic dagger
empty pelican
dusk cedar
#

can anyone help me with this differential equation

left knoll
#

I am a three-digit number,
The sum of my digits is 7.
Multiply me by 5,
And you'll reach a number that's alive.
Add 200 to that number,
And the result you shall uncover.

The number you get after solving this puzzle is smaller than the main number (Guess the number)

Riddle number < The correct number*

2nd Hint for stage 1(Gues the number) :-

(500 + 200) - (400 / 2) + (150 * 2)

The number you get after solving this puzzle is Greater than the main number (Guess the number)*

Therefore if you get the solution to 1st and 2nd riddle

1st Riddle number < The correct number < 2nd Riddle number

weary arrow
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I get two answers

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It's worded so oddly but I'm assuming that
1st Riddle number = 'x' (sum of digits = 7)
Correct number = 5x + 200
2nd riddle number = (500+200) -(400/2) + (150*2) = 800

That gives x<120, which gives x=106 or x=115
And then the correct number would be 730 or 775

left knoll
#

hi

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i need some help with indefinite integration

gray veldt
#

x^2 = t

left knoll
weak lotus
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will make things wayyy easier

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@left knoll

gray veldt
surreal cypress
# left knoll

f is injective
is equivalent to
there don't exist pair of different values x,y such that
f(x)=f(y)

f(x)=f(y) is equivalent to
(x-y)(x²+xy+y²-1)=0
so
there don't exist pair of different values x,y such that
(x-y)(x²+xy+y²-1)=0

which is equivalent to
there don't exist pair of different values x,y such that
(x-y) = 0 or
(x²+xy+y²-1)=0

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which is false
because x²+xy+y²-1 can be 0 when x≠y

left knoll
#

Hello can someone help me with math problems?

left knoll
#

Post it here@left knoll

cunning oasis
#

Find the temperature distribution in a semi-infinite plane with a width of 20 cm if the temperature at the bottom is 𝑇 = 𝑓(𝑥) = 𝑥, and the temperature at the other edges is maintained at 0 degrees.

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can someone help me with this problem? thanks

clever talon
#

Can someone tell me the meaning of this

pale agate
# clever talon

as far as i know there's some psychology scientists invitend laws like that

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there's :the subjective sensation is proportional to the logarithm of the stimulus intensity.

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i don't know about this one tho lol

odd pivot
#

Since ABC is a triangle [AB] is a bisector of this triangle, and DEFK is a square, find the angle measure DCL

weak lotus
#

i cant really see the lines

odd pivot
weak lotus
#

and shoudnt it be (ad) as a bisector

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isntead of ab

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thank you very much!

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i see what you need to do

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ill give you a tip wait

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You can use this

odd pivot
#

@weak lotus Thanks for everything I found the solution to the question from another friend of mine

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It was difficult to understand what they were saying because my English is not perfect

weak lotus
#

oooo

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all good man!

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geometry is pretty versetile, a lot of ways to get to the answer

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good luck

solar drift
#

kinda stuck at this question, can someone help?

unborn creek
#

simplify: lim (x->0) 4*arctan((x+1)/(2x+1))-pi/4x
Then we use L'hopital: lim (x->0) (-4/(5x^2+6x+2))/4
Plug in 0 for x: (-4/2)/4 = -2/4 = -1/2

gusty flower
#

for osme reason when i put "Factor 3x^2 + 4xy + y^2" into my CAS it just comes up with the equation as the answer

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anyone know how to fix?

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the answer ik is (3x+y)(x+y) but it dont show on the cas

torn trellis
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prove that x^4+4 is prime only for one value of x belongs to natural number

ripe cargo
#

İ find it by trying , can u post the solution

torn trellis
gritty sleet
torn trellis
#

no let me write the entire stuff

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x^4+4=x^4+4x^2+4-4x^2

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(x^2-2x+2)(x^2+2x+2)

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what to do next

gritty sleet
dawn inlet
mystic thunder
#

omg BRO 😘

feral moth
#

guys
in the vertex form formula: y=a(x-b)^2+k
what does k equal to? in quadratic

ripe cargo
empty pelican
feral moth
ripe cargo
feral moth
#

thanks ❤️

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and I am guessing b is the x value of vertex right

ripe cargo
#

and we also can say axis of symmetry to b

feral moth
#

yes, I get it

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thanks again

ripe cargo
cunning oasis
#

is there any way or any math symbol that can denote modified factorial operation,for example 6!=6x5x4x3x2x1x0 but i want this way (6x5+1)(4x3+1)(2x1+1)?

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or can i use substitution for example k! where k is k(x)

left knoll
#

Why not just write Prod_{k=0}^{5} [(k+1)k +1] with Pi symbol for product

cunning oasis
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yeah i never know the name of capital pi before, or any ideas what is that symbol, thanks

fringe trellis
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hi does anyone know how to solve c??

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literally have no idea

tribal iris
#

Can I theoretically reduce any improper integral of the second kind to an integral of the first kind (to generalize the convergence criteria) using substitution and integration by parts?

left knoll
#

Can someone dm me asap if they are able to help me with quadratic functions and equations, trig, rational and reciprocal functions, systems of equations and inequalities, and substitution and elimination (if you can help me with one of them please dm)

unique coral
gray veldt
#

Still you will get the same answer mentioned above

gray veldt
left knoll
#

Hii im studying physics and i was doing really well until this

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translation: "calculates the force (module, direction and sense) that will act on the conductor" The thing is, i dont understand why the sen is 90° and why the result is written like that?

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other than that i understand it, but the guy in the video doesn't explains the questions i made Jamesstudying

gray veldt
#

@left knoll THe length vector is along x axis

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and magnetic field is along z axis

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so alpha = 90

weak lotus
# unique coral True?

As dream suggested you take u as 1 + x^2. You have to make it yourself as easy as possible. Good solving but time is key 😁

fiery widget
#

for b) (i) you use the answers you get for a) which are (0,3) and (3/2, 0) to find the values for a

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to get the first value of a you set y=ax+2 to 0=3/2a+2 which you end up getting a =-4/3

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but for the other value of a you need to do (y2-y1)/(x2-x1) = a to find the other value for a

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but how do you know wether is (y2-y1)/(x2-x1)<a or (y2-y1)/(x2-x1)>a ?

gray veldt
#

since we dunno whether it intersects at the same point

fiery widget
gray veldt
#

yeah

fiery widget
#

but i dont know which one its gonna be

gray veldt
#

take union

fiery widget
#

well i do because ive seen the mark scheme

gray veldt
#

both can be done

fiery widget
#

what union?

gray veldt
#

-infinity to -4/3

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wait a sec

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ahhh

fiery widget
#

the way I think of it is for when y=-2x+3, a > -4/3

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and then a < 2 for when its y=2x-3

gray veldt
#

the given unknown line intersects x axis at x = -2/a

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try drawing a graph

fiery widget
#

yea

fiery widget
gray veldt
fiery widget
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cause when 3-2x=ax+2

gray veldt
#

it aint

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dude take y=0

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intersecting x-axis

fiery widget
#

oh yea my bad i was thinking of the next step

gray veldt
#

ohh

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well if -2/a lies in the negative side then

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-2/a < 3/2

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so a>0

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typo error mb

fiery widget
#

but wont a = 2

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because to work out the two values of a

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firstly you do (y2-y1)/(x2-x1) = a

gray veldt
fiery widget
#

which you end up getting -2 = a

fiery widget
gray veldt
#

can you send your rough work?

fiery widget
#

yea sure give me a sec

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a = -4/3 for the left side *

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I think the set of values for a is

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-4/3 < a < 2

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Because rise/over run has to be less than a

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As then a will become a < 2 instead of a > 2 because then we get no upper value as we -4/3 has to be the lower value

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If that makes sense

gray veldt
#

well y=0 and x=3/2 is the poi of the one of the equation

fiery widget
#

yea its where x intersects the y axis in y=-2x+3

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and i used it cause then you would have 3/2=0*a+2

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and then you cant find out what a is

gray veldt
#

it doesnt even pass through it

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idk, you cant use it like that

fiery widget
#

oh bruh so i used illegal maths

gray veldt
#

yeah fr xD

gray veldt
fiery widget
#

the question asks for domain, would I still be able to use it

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wouldnt I just do

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2x-3=ax+2 and 3-2x=ax+2

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and then work out the individual x-coordinates of in terms of a

gray veldt
#

you can do that way

fiery widget
#

okay cool

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thanks alot, even thought I ended getting arrested by the maths federales

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appreciate it

gray veldt
#

it will something like a belongs to (-infinity,-4/3) U (0 to infinity)

fiery widget
#

okay cool thanks

#

extra knowledge 🗒️ ✍️

clever talon
#

Can anyone help me with no. 6 pls

gray veldt
#

you're studying for neet right, why did they gave you maths hw? (if u dont mind)

gray veldt
#

Hint:- check in 4th quadrant

weak lotus
#

Can someone help me with this one

#

2sin^2(x).e^-xdx

left knoll
#

Use Euler formulas

weak lotus
#

Appreciate it

deft apex
#

How do I now if the given vector set is spanning or not if the set is not an square matrix. For example a R^2 but with 3 vectors?
v₁ = [1, 2]
v₂ = [3, 4]
v₃ = [-1, 0]

sudden tiger
deft apex
#

is it these theorems

deft apex
sudden tiger
sudden tiger
#

there will be infinite number of solutions

deft apex
# sudden tiger yes

question if I were to turn the vectors in a matrix
1 1 -1
2 3 0

and using by gaussian elimination, the answers are
x1 = -3
x2= 2

does this mean it is spanning?

sudden tiger
#

ii don't know how you can apply gaussina elimination here
you have system

x = a + 3b - c
y = 2a + 4b

solve it however you want

including gaussina elimination

but it is simpler to solve it as usual

with substitutoin

midnight grail
#

Could someone help me out with 1(c)?

unborn creek
#

Look at moment generating functions for normal distributions and then connect them with the normal CDF

prime hinge
#

can someone tell me why this is not a function?

prime hinge
#

is it because y is ^2?

wet trellis
#

The equation (x^2 + y^2 = 1) represents a circle, an equation for a circle can’t be a function. In order for an equation to represent a function, each input value (x) must correspond to an unique output value (y).
If you solve the equation for y, y = +- sqrt(1-x) there are two possible values of y for a given x. So yes it’s because of y^2

prime hinge
#

how do you know if it represents a circle without looking at it on a graph?

amber vapor
prime hinge
#

sorry I don't understand this

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I'm very bad at math

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But i managed to understand how Function represented as ordered pairs work. same with Mapping Diagram

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Now im trying to understand function represented as "Equation"

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but the video tutorial that I am following on YouTube failed to explain it to me

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I only know that if the vertical line intersects more than one in a graph, it is not considered as a function. btw this math topic is called Functions As Models

weak lotus
#

have you seen implicite and explicite functions?

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that explains when a function is a function or not

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if we can write a function in only one way like y= its mostly a function

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but if its y^2 we will have more outputs then we are allowed to generate

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a circle is not a function because if you draw a line perp to the y-axis is crosses the "function" twice

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its a graph, not a function

prime hinge
#

Can you recommend a YT video abt it that will help contribute on my understanding abt functions?

weak lotus
#

ill search one wait a sec

left knoll
#

Send the Sol if you do...if you wish

rapid onyx
#

that is

#

what is written says Is because we dont know the sign of the term (x+4) we cant take the solution -5, i wanted to know how one can know which solution goes (in this case is -1), because the two of them are negative, the problem would be that we dont know with certainty the sign of the x right ?

versed gyro
#

Can anyone do that and explain
Please 🥺

#

Number 6

solemn vessel
#

@versed gyro They tell you in (a) that your house is TWICE as old as your neighbors house

#

… that’s all the info you need really

versed gyro
#

got it @solemn vessel

#

thanks a lot my bro 🫶

surreal cypress
#

check
√((2•(-5)+11) +5-4=0

#

if true then -5 is the solution

frigid basalt
#

Hey guys, a quick question about determinants and eigen values, if I have the characteristics equation Det(A-Iλ)=0 and I preform rowoperations on matrix A, how do I keep check of the determinant? am I even allowed to do row operations on matrix A?
becuase the determinant is not closed under addition

frigid basalt
#

Alright, already figuerd it out!

barren basalt
#

Hey pal, can anyone here recommend me a crash course in microeconomics? I really want to prepare for next semester, but I don't have materials and have no idea where I can find good ones.

weak lotus
wide jasper
gray veldt
#

you mean monotonic?

torn trellis
#

nope basically

torn trellis
gray veldt
#

well try writing it as f(x) = g(x) - x

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damn it would be easier if they have given the value of f(6)

#

its 3am here, I will try this question in the morning see ya

surreal cypress
#

Did u get this?

#

f(x) =x⁶-15x⁵+85x⁴-225x³+274x²-121x

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here's the funtion

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by the definition of a monic polynomial, a₆ = 1

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so your polynomial has form
f(x) = x⁶ + a₅x⁵ + a₄x⁴ + a₃x³ + a₂x² + a₁x + a₀

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@torn trellis

torn trellis
#

ohhhhhhhhh thank you so much @surreal cypress

knotty zodiac
#

anyone good with calculation of physical chemistry

fiery dome
#

Anyone know the simplest way to simpify this without the use of a calc?

#

Looking how I can make this into sq(3/2)

fiery dome
# left knoll

Thanks, I feel quite dumb now that I see it
Appreciate it!

crisp topaz
#

anyone know how to split into those two brackets?

shy otter
#

Can someone help me? I make the substitution but I think I make it wrong

timid delta
#

ig that will solve it

solemn vessel
#

do you know how to take the determinant of a matrix?

crisp topaz
weak lotus
#

Solve for x and fill in

#

Simple as that

shy otter
# weak lotus

yo thank u very much!! it took me a while to understand it but I did

weak lotus
undone ledge
#

Hey can someone help me out with question 2?

#

I got 2a+h^2 +2a

#

But it’s not on the choices 😭

#

I feel like I did something wrong

#

But idk ahh

surreal cypress
#

ROC = (f(a+h)-f(a))/h

#

D

sudden tiger
undone ledge
#

@sudden tiger

undone ledge
#

I’ll try again 👍🏽 thank you @surreal cypress

cunning wharf
# undone ledge

not sure if you still need it but here’s how i did it and got the answer

cunning wharf
#

no problem :)

surreal cypress
vale crater
#

can someone tell me how the mandelbrot set works

stoic ember
#

can any one explain the marked step

onyx yoke
#

Is any one a med student here

stoic ember
#

@onyx yoke check the medic-help channel

onyx yoke
#

Thank you!!

surreal cypress
#

S = 1/(1+x) + 2/(x²+1) + 4/(x⁴+1) + ... +

#

S + 1/(1-x) = 1/(1-x) + 1/(1+x) + 2/(x²+1) + 4/(x⁴+1) + ... +

#

S + 1/(1-x) = 2/(1-x²) + 2/(x²+1) + 4/(x⁴+1) + ... +

#

S + 1/(1-x) = 4/(1-x⁴) + 4/(x⁴+1) + ... +

#

S + 1/(1-x) = 8/(1-x⁸) + .... + ...

stoic ember
#

Thanks

#

But ...i stil demand explanation for why it was Added on both sides

surreal cypress
#

U can add anythjng to both sides of any equation

for example x + 2 = 3

#

i randomly decided to add x to both sides of the equation

#

the equation remains equivalent

#

can add 1/(1+x) to both sides because I want so

#

x + 2 + 1/(1+x) = 3 + 1/(1+x)

#

in this case theres the equation

#

S = 1/(1+x) + 2/(x²+1) + 4/(x⁴+1) + ... +

#

you decided to add 1/(1-x) to both sides of the equation

proven hinge
#

Need any help...maths genius is here1812_wutcat

weak lotus
proven hinge
weak lotus
#

what problem you trying?

spice perch
#

Are there some experts at modular arithmetic here?

loud spear
#

The next term in sequence 1,3,6,11,20,37,?

#

options are

#

(1) 65 , (2) 67 , (3) 70 , (4) 60

#

with explanation please

weak lotus
weak lotus
#

3rd line is x2 so after 8 we have 16

#

16 + 17 = 37

#

And thats correct

#

So 16 × 2 = 32

#

2nd line is plus 1, 2, 4, 8

#

So that gives us 16

#

Plus 17 = 33

#

33 + 37 = 70

#

Answer 3

cyan haven
#

how many hours should i aim for to learn all of precal

wanton crag
#

are you still in high school? if so that might take couple of weeks with constant studying

#

but if you've already graduated is more simple

cyan haven
loud spear
#

Everyone be advised please try to ignore this it is a scam as you will click it it will take on your person information be aware of your surroundings please confirm before clicking on the link. I'm just a random who came by to know that this is a scam, just spreading the word around.

inner cargo
#

Could someone help me please, thanks 👍

loud spear
#

Everyone be advised please try to ignore this it is a scam as you will click it it will take on your person information be aware of your surroundings please confirm before clicking on the link. I'm just a random who came by to know that this is a scam, just spreading the word around. As i have said before about some other spam with same info too.

shadow solar
#

Hmmm looks like math to me

teal karma
#

Hello can someone please help me in any of them

wanton crag
left knoll
#

Hi, i am a beginner at math, can someone help me?

timber cedar
stuck bane
#

Which is a better book for calculus

#

Thomas calculus or tom apostol

weak lotus
left knoll
#

a shape made of 12 cubes

#

how many different ways to go from point K to point L using the shortest path?

#

is it 210?

#

my solution;
7!/2!x3!x2! = 210

#

@calm galleon

sweet fractal
#

LOL my guy just <@&1050536614306267217>ted the man himself looooooooool @left knoll

wanton crag
loud storm
#

Guys I need help

#

For what value of the variable will The value of 3 - 5c be 1 less than the value of 1 - c

amber vapor
#

3/4 ?

#

is the question that simple or c is some higher like academic term stuffs that i have no idea about lol

lilac vigil
surreal cypress
undone ledge
#

Hey could I get some help for question 14 tysm :))

weak lotus
undone ledge
#

Ricos?

#

@weak lotus

weak lotus
#

Thought the dutch word was the same as the english one

undone ledge
#

Ohh 😂

weak lotus
#

You use derivatives to find minima and maxima

undone ledge
#

Ohhhhh

weak lotus
#

Yes 😉

#

I assume you found the light 😂

undone ledge
#

Oh yeah if you find minima that’s how you get question b

weak lotus
#

The SAME is also a hint

undone ledge
weak lotus
#

That means they are EQUAL to eachother

#

C and d is just knowing what they ask and what your function tells you

undone ledge
weak lotus
#

Jup

#

Im not gonna give the answers because thats not how you learn, so try it yourself! Im sure youll get there 😁

undone ledge
weak lotus
#

Yes

#

Lets go!

undone ledge
undone ledge
weak lotus
proper yacht
#

hello, does anyone know how to count area in between curves using integrals? :((

amber vapor
#

like acreage ?

proper yacht
#

this area

amber vapor
#

just let two y equal, you will have x^2-9=3x-x^2
solve the equation
then integral the absolute value of 3x-x^2-x^2+9 with thoes two x you just got

#

use your calculator tho

proper yacht
#

oke ill try

#

thank you very much @amber vapor PeepoLove

shy otter
proper yacht
proper yacht
amber vapor
#

to be fair subtract the other way around will give you the same anwser since it in absolute valute, however you would like your mindset to let the above one subtract the under one

#

like in some implicit function problems you should always subtract the above one to the lower one cause some question wont trick you but some will do so even if it gives the same result just subtract the above one for the lower one, just to be safe lol

ocean imp
#

somebody studying linear programming?

lilac vigil
#

the solution to this question is to solve for x in terms of y using the quadratic formula. But what would happen if you solved for y in terms of x using the quad formula? I tried this but I ran into some problems which to me doesn't make much sense cuz it's the same idea. Can anyone explain or help me with this?

ocean imp
#

You can change the order of the incognits how you want to as long as you respect the value of each one of them. It would be the same as pretending x is a and y is b or vice versa

#

In short, the difference is that when clearing a variable, you are saying that this variable is the dependent one. That is why the values ​​would not be the same if you do not respect their meaning

#

Also the quadratic formula is to find the roots once you have already simplified it all. If you pretend they're y you're basically searching a 2 tigers in the ocean lol

#

Hope that helps

lilac vigil
lilac vigil
mystic thunder
#

the solution is pretty weird

lilac vigil
#

If you want there's a video that cover this

#

It's by the university of waterloo

mystic thunder
#

oh makes sense

ocean imp
#

In this case you would have to make 5 a 2 and 2 a 5 for X^2 and Y^2

lilac vigil
#

Basically something like his and then you solve?

#

Cuz that's what I had in the beggining

#

But when I tried to do quad formula on it the discriminant had an unfactorable equation

ocean imp
#

f off

undone ledge
#

Ahh I’m confused on question b

earnest whale
#

hello

muted zenith
undone ledge
left knoll
#

Can you help me with my questions about statistics?🥹🙏🏻

heavy acorn
#

Anyone know how to find x?

hard fiber
hard fiber
#

hope it explains 🙂

left knoll
shrewd flume
#

Help please I need to answer question 4 in 30 minutes can you help me?

timid delta
still steeple
#

Hi, is there someone that could help me to finish a three phase exercise (electrical engineering stuff)?
I'm stuck and don't know how to continue it

lime yarrow
fallow forge
#

this cost matrix assignment problem i need optimum cost and right circle

lime yarrow
#

I dnt speak turkish

fallow forge
#

its not about translate I gave enough information for someone who might know how to solve

limber oriole
#

anyone know how to find inverse of abs func

distant pebble
#

I think

lime yarrow
#

case 2: 3-x<0
y=-3+x
x = y+3
f-1(x) = x+3

limber oriole
#

there are 2 inverse funcitons?

#

for absolute fns

lime yarrow
#

inverse function f-1
f-1(x) =
3-x if x≤3
3+x if x>3

limber oriole
#

thank you @lime yarrow

lime yarrow
#

np

left knoll
#

can anyone help I don't know what to do

weak lotus
#

F-1(x) is swapping x with y and y with x. Solve for y and determain for what x values the function exists

weak lotus
#

So you get an rational function

limber oriole
wintry olive
#

I've been stuck on this physics problem for hours now so if anyone could explain how to calculate this it would be of much help

frigid wave
# wintry olive I've been stuck on this physics problem for hours now so if anyone could explain...

I think the first one should be I = m1 * x1² + m2 * (x1 + x2)².

And for the second one you need the "Satz von Steiner" (I don't know the english translation and I can't google search because my Internet Provider is Brokey Mokey). Basically, you take the moment of inertia for a rod when the rotation axis would in the middle (search for the formula, should be I = 1/12m * length_rod²) and just add the additional Inertia I = m_rod * d_Offset², where m_rod is the mass of the whole rod and d_offset is the distance from the middle of the rod to the axis. Not 100% sure as I had to do this like a year ago when I still studied mechanical engineering. But this should be right

wintry olive
#

I agree this sounds right

#

But I tried the exact same equation for the first one and the result is super duper small and says incorrect

#

yea i get 6.1394*10^-5

#

for the first one

frigid wave
#

Welp, imma try it myself gimme a few minute

wintry olive
#

thank you sm 🙏🏻

frigid wave
#

inb4 its wrong because your prof does some weird rounding shenanigans 💀

wintry olive
#

omfg that COULD be it

#

happened in the past

#

fucking professors

#

that was it

#

rounding

#

im gonna kms

frigid wave
#

welp

wintry olive
#

welp

#

thanks

frigid wave
#

no problem lmao

wintry olive
#

i really appreciate ur help

#

have a good day, internet stranger

frigid wave
#

u 2

#

or smth smth

wintry olive
#

yes yes

torpid ember
torpid ember
#

I do understand ax^2 + bx + c > 0 graph will have it's parabolla in such a way that it won't cut the x axis for the eqn to be > 0.
There the discriminant, D<0
But the thing is if D<0 then the question says that the roots are real but if D<0 then it's roots will be imaginary and imaginary are not real

timid delta
ionic cloak
#

First understand this and then memorize it. Use flash cards or cover parts of it with hand or page to help you memorize.

foggy sparrow
#

can anyone help with Vu and Vi? how is it calculated... B=2pi and T=-1/3, and im not sure what of the value of y from the question.

onyx roost
#

hoiw do you know that member a is going clockwise

left knoll
#

My math exam was horrible
Any tip to get better at maths

#

I am 9th standard

compact trench
mystic thunder
mystic thunder
#

hii, can someone please help me with the concept of percentage and money related stuffs? im stuck on this question : Price of a car is reduced by 20%. Sale is increased by x% and output is increased by 25%. Find the value of x.

still briar
#

first, the price of a car is reduced by 20%.This means that the price is now 80% (100% - 20%) of its original value.

#

then, the sale is increased by x%. Let's denote the increased sale as S. The new sale will be the original sale plus the increase, so it will be S + (x/100)S.

#

The output is increased by 25%. Let's denote the increased output as O. The new output will be the original output plus the increase, so it will be O + (25/100)O.

#

Now, we need to find the value of x, which represents the percentage increase in sales.
According to the problem, the price reduction leads to an increase in sales and output. Therefore, we can set up the following equation:
(Price of car after reduction) × (New sale) × (New output) = (Original price) × (Original sale) × (Original output)

#

Using the information we have, we can substitute the values:

(0.8) × (S + (x/100)S) × (O + (25/100)O) = (1) × (S) × (O)

#

Simplifying the equation:

0.8(S + (x/100)S)(O + (25/100)O) = S × O

#

Expanding the equation:

0.8(SO + (x/100)SO + (25/100)SO + (x/100)(25/100)SO) = SO

#

Cancelling out the common factors and simplifying:

0.8 + 0.2x/100 + 0.25 + 0.2x/400 = 1

#

Combining like terms:

0.8 + 0.002x + 0.25 + 0.0005x = 1

#

Combining the numerical values:

1.05 + 0.0025x = 1

#

Now, we can solve for x:

0.0025x = 1 - 1.05

0.0025x = -0.05

x = (-0.05) / 0.0025

x = -20

Therefore, the value of x is -20.

mystic thunder
#

but the value of x given in answer key is 56.25 % :(

#

either im not able to interpret the question or doin sum wrong

left knoll
mystic thunder
# left knoll Ya

OK EZ u just needa be disciplined in doing math, do ncert 3 times (once in school, once as school homework and one as practice) giving special emphasis on proof questions + examples in ncert. after each chapter do rd (not everything but cover ALL different patterns of questions) and get ur doubts clear then and there DO NOT hesitate. that's all u needa do also better focus in class

weak lotus
opal echo
#

I scored full in 10th

#

Not exactly full

polar osprey
#

Should'nnt P(7) be 6/36 and P(11) = 2/36? Ik the answer is correct but ii don't understand how P7 and P11 have equal favorable cases as shown below

solemn vessel
#

<@&942391219206647828>

#

the above links are in every channel

#

fake youtube links i think

unreal plaza
icy dragon
#

Hello I am looking for a math online course can someone recommend any?

undone ledge
#

Could someone help me with this 😅😅

#

I feel like I’m overthinking it..

left knoll
undone ledge
undone ledge
#

Could I get some help with question 19 a

somber yarrow
#

2 is the factor

#

lemme send the pic

somber yarrow
plain flume
#

need help from someone to explain me why does it turn into this

autumn zinc
#

@ me if there’s a part you don’t understand

mystic thunder
#

atleast they took the effort to type it in gpt 💀💀

sudden tiger
#

Yep

sudden tiger
mystic thunder
undone ledge
plain lantern
#

Hello
¿Someone here have a proof of why cos(2x) = 2cos(x)^2 - 1?

red pumice
#

can someone help me get why x >-1 matters

left knoll
undone galleon
#

hello guys

#

what about an imo competition , guys?

#

anyone participate may be ?

left knoll
left knoll
left knoll
lunar ginkgo
#

hey - i know how integration by parts for indefinite integrals work and i also know what definite integrals are, yet i don't understand the following:

why are we allowed to just adjust the integration by parts formula so that it looks like in the picture?

solemn vessel
#

Are you asking why the bounds appear where you have highlighted?

#

If so, you might want to refer to a derivation of the method and/or a proof of why it works, if you want to understand it in depth

#

Or are you asking why L is used?

snow eagle
#

someone help me

shy totem
#

how do you find the square root of 573800 ?

errant totem
lunar ginkgo
lunar ginkgo
solemn vessel
lunar ginkgo
brittle sluice
#

I have doubt can I hear music while solve math problem

shy totem
#

university entrance

#

the problem was like this: basically, we got the surface area for the pyramid and we need to find the side lenght

lunar ginkgo
shy totem
#

ty!

mystic thunder
solemn vessel
#

or when taking an integral during the derivation, do the same thing

#

the derivation will be the same

undone ledge
#

Can I get some help with question 9 please?

sudden tiger
#

this

#

this one is cancelled out

#

limx->2 = 2
-1 + 2 = 1
Then the answer is 1

sudden tiger
lunar ginkgo
meager halo
#

Abhi_Codz: Status
**afk: **
Tomorrow's my math exam lol
Wish me luck for preparation, wish me luck during exam time, wish me luck for results
And yeah, if you believe in god, please pray for me to do good..Atleast 26+ out of 40

solemn vessel
#

Is anyone here familiar with the laplace expansion of the determinant in terms of complimentary minors?

#

More specifically, how it applies to a special subet of 2Nx2N matrices

scarlet canopy
#

I have the role of deputy Director General, Supervisor and many other in my discord server, If anyone is interested in war, military, conflict and geopolitical stuff than contact me.\

undone ledge
undone ledge
#

Could I get some help for question 6?

#

I’m not sure how to “ show” it :// thank you!!

left knoll
# undone ledge

x^2 - a^2 = (x-a)(x+a)

the equation will be (x-a)(x+a) / (x+a) it's equal to (x-a)
so the function is f(x) = x-a , a is any number in R except the -X
so the first derivative will always be 1

undone ledge
undone ledge
#

Hii I’m a bit confused on this question :// any help would be super appreciated

gray veldt
#

apply this you will get your answer

timid delta
#

nice

left knoll
#

just want to make sure, in a problem like this i add 2 to every element in the vector of x? so it would be <4; 3; 4>?

#

or is it undefined because you can only add when the number of elements is the same?

gray veldt
#

I guess here we have to take the magnitude of the vector

solemn vessel
#

xbar, here, is a vector, and thus (e) would not be defined

undone ledge
#

Yeahh I’m just a bit confused like… for the formula you can use it if your approach from right or left.. so I was wondering which one to use

twilit osprey
#

Can anyone tell me how we got from Point A to Point B here? I feel like it's really simple but I'm blanking. It's part of a calculus 2 polar coordinates problem

tiny isle
#

I tried to simplify it

twilit osprey
#

Thank youu!

#

That was actually so simple lmao my brain fog has been bad today

undone ledge
#

Could someone go through how to differentiate these two questions step by step.. I keep getting confused with the square roots ahh

#

Thank you so much

weak lotus
#

Chain rule

#

And the top one is just the rules of derivation

fading shuttle
stable widget
#

Hey guys. Do yall know how to draw logistics regression graphs on excel? Is that even possible?

clever talon
#

Can any help me solving this inequality

dire aurora
#

@left knoll Does the asymptote x = -a exist for the f(x) -= x-a from that question?

#

@clever talon

#

not fully confident tho

left knoll
dire aurora
#

Felt like it does

vale wyvern
# clever talon

the denominator which is (x^2 + 3) will always be positive for all the values of x here,
so you need to solve for,
5-3x < 0
which turns to
x > 5/3
and given x< pie
therefore,
5/3 < x < pie

vale wyvern
dire aurora
#

🥧

#

The greatest

left knoll
twilit osprey
#

Does anyone know what is happening at the part that I circled?

#

I'm taking Calc 2 online at a community college so I basically have to teach myself

#

I don't understand why we are multiplying by 1 over cos(2theta)

left knoll
twilit osprey
left knoll
#

can anyone please help me on this one

left knoll
# left knoll

cot(π/3) = cos(π/3)/sin(π/3) = 1/√3
csc(π/3) = 1/sin(π/3) = 2/√3
cos(π/4) = 1/√2

(1/√3 + 2/√3)/(1/√2) = (3/√3)/(1/√2) = √3 * √2 = √6

plain lantern
#

Hello.
Someone know if is possible find the roots of a polynomial of degree N+2 having as only information a finite list of random points of said polynomial and knowing what is the degree of that polynomial?

clever talon
#

Can we cancel out the factorial from both sides like this?

cold raven
#

With the mean being 18 and the SD being aprox 2.12. I dont understand the answer to d) if anyone can help

supple stump
clever talon
#

Thank you but I was talking about 10-r

slender temple
#

how does this work?

weak lotus
#

Since above is a dubblr profuct

#

(A-b)(a+b)

#

So you erase the a-b on top of botom

#

You can do the same with x and y to make itt easier

slender temple
left knoll
left knoll
cold raven
rich dome
#

can anybody do these 2 questions

undone ledge
#

Could I get some help on this

weak lotus
#

Meanq the derivative is equal to 0

#

So derive and find the zero points

#

@undone ledge

undone ledge
#

@weak lotus thank so smm

sturdy mist
#

i put true for this since if Ax = 0 only has trivial solution then the vector components must be linearly independent, so A must span all of R^m but that was wrong, can someone please explain why

sturdy mist
# rich dome

for 14. use the z-scores for 95% and 99% confidence then multiply them by Sx to find the respective +/- on mean

supple stump
ashen lagoon
#

Does anyone here know any resources for learning basic maths?

ornate ocean
#

can anyone please help me on this one

timid delta
#

2= log(4) (as base is 2)

#

then use properties of log

#
  • means multiplication
#

" - "means division

#

then just solve normal equation

undone ledge
#

Hi

#

Could I get some help with question 7 please :))

#

8**

ornate ocean
# undone ledge

first find the derivative of the function and set derivative equal to zero and solve for x. to find the corresponding coordinates, plug those x values back into the original function and u will get the coordinates

unreal schooner
obtuse citrus
#

who has a decent understanding at statistics here?

#

i don't understand at all how they calculated the mean and the variance

#

it doesn't make sense

#

btw opportunity = probability (bad translation lol)

mint vortex
#

standard deviation is if im not mistaken probably calculated here as a square root of variance probably

random atlas
#

Anybody please recommend me some good books to study pure mathematics

#

I’m currently preparing for jee but wanna study higher mathematics too

random atlas
#

Thank you so much

solemn vessel
#

if you are new to pure math definitely do not start with a lot of those books unless you have a solid foundation.

#

Spivaks calculus is good if you’re looking for a more rigorous introduction to calculus/ an introduction to analysis.

#

how to prove it is also nice if you’re new to proofs

random atlas
#

Okay I’ll try them first

solemn vessel
#

Otherwise many of those books are very advanced

#

looks like a chatgpt copy and paste tbh which i see a good amount of people doing 😂

random atlas
#

I think I have basic foundation

wanton crag
#

can someone help me with this one? it is from the Essential Linear Algebra with Applications, by Titu Andrescu

celest escarp
#

Can someone help me with the third one? Basic trigonometry

floral marlin
#

hello, can somone help me with this problem: Find all two-digit natural numbers with the following property: When you add the number to the sum of its digits, you get 62.
Hint: If the number is in the form xy, then xy + x + y = 62.
I have tried and I cannot find a number like this. Is this even solvable or is the answer actually that a number like this doesnt exist? thank u!

timid delta
#

Hmm

#

Oops

#

Let the number be 10x+y

#

10x+y+x+y=62

#

Hmmmmmm

#

11x+2y=62

#

If u put x=4, then

#

Y=9

#

So the number is 49

#

@floral marlin

floral marlin
#

thank u!

timid delta
#

Np

acoustic crater
mint vortex
prime minnow
#

Integration by substitution
From blue pen down, 1st line is from the solution, we're given u=x^1/2 as a sub. 2nd & 3rd line is me trying it, where did it go south?

mint vortex
#

let f(x,y) = |x - y| , then
|x1 - y1| + |x2 - y2| != |(x1 + x2) - (y1 + y2)|

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tho in that case

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|x - y| would mean the distance between the coordinates x and y as real numbers

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not a distance of vectors v = (x1,y1), w = (x2,y2)

mint vortex
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but for what function did you substitute?

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because i see two functions there

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f(x) = 1/x and g(x) = sqrt(3x - 2x^2)

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if you want to substitute for g(x) then you need it's derivative out in the integral right?

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is that where you get sqrt(2) from???

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kinda confusing

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unless it's like 1/x composed with sqrt(x) whose overall composition is then composed with 3x - 2x^2

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but that makes me even more confused

mint vortex
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what i noticed

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

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3x - 2x^2 != 2(3/2 - x^2)

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Since you did sqrt(2(3/2x - x^2)) then use sqrt(ab) = sqrt(a)sqrt(b) to pull out 2 out

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you got sqrt(2)

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But where the x at???????

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😕

prime minnow
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also can you tell me which line you're talking about :'D?

mint vortex
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sqrt(3/2 - u^2)

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Shouldn't it be sqrt(3/2u - u^2)

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Like where the u at

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it disappeared

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????

prime minnow
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is it the last line?

mint vortex
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I dont which line idk how you count them

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Its the first line below "FROM SOLUTIONS"

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if that helps

prime minnow
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yes it does, that 1st line below "FROM SOLUTIONS" is copied from the lecturer's solutions. I dunno how he got there

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I keep getting a different answer

mint vortex
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Are you sure he didn't forget to put 3/2u ?

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Look

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Sqrt(3x - 2x^2)

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You pull out 2

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

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You get Sqrt(2)Sqrt(3/2x - x^2)

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but then he somehow subs

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And gets Sqrt(2)Sqrt(3/2 - u^2)

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Shouldn't it be Sqrt(2)Sqrt(3/2u - u^2) ???????????

prime minnow
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yours is right but i still need to get it in the form

mint vortex
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Oh wait

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Unless

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@prime minnow i got idea maybe

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OOH

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what if he pulled out x too

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sqrt(3x - 2x^2) = sqrt(2x(3/2 - x))

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But like