#precalculus

1 messages · Page 194 of 1

trim fable
#

oh well

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ill just do this tom

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so cya 😛

clever inlet
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cya

trim fable
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or later idk

viscid thistle
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how do I find the maximum and minimum of y=sinx+sin2x

willow bear
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what have you tried and where are you stuck

viscid thistle
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ok

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I tried adding the amplitudes of both

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didnt work

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factoring out sin doesnt work since it changes the equation

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and it's the last problem on my math homework

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and I wanna go play CSGO

willow bear
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hang on. given that you're posting this in #precalculus rather than #calculus, i suppose you're not supposed to use derivatives

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is that correct

viscid thistle
#

yyea

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im in precalc

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derivative isnt that just slope or seomthing

willow bear
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forget it

viscid thistle
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iidk I take calculus next year

willow bear
#

why not use a sum to product identity then

viscid thistle
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what

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is that

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u mean sum and difference forumula?

willow bear
#

$\sin(x) + \sin(2x) = 2\sin(\frac32x) \cos(\frac12x)$

obsidian monolithBOT
viscid thistle
#

so it is 2

willow bear
#

maybe

viscid thistle
#

0.o maybe

willow bear
#

the maximum value cannot be greater than 2

viscid thistle
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why

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ohbyea the amplitute XD

willow bear
#

because sin and cos are both bounded by 1

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so $2\sin(...)\cos(...) \leq 2$ no matter what the contents of those sin and cos are

obsidian monolithBOT
willow bear
#

if it so happens that there exists a point for which 2sin(3x/2)cos(x/2) is equal to exactly 2, then congratulations, that's your maximum value

viscid thistle
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nani

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ur math seems confusing

willow bear
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what part of what i said is confusing?

viscid thistle
#

bounded by 1

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I know the range is only 1

lilac pier
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Ann may I say something

willow bear
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i'm saying $\sin(t) \leq 1$ and $\cos(t) \leq 1$ for all $t$ @viscid thistle

obsidian monolithBOT
willow bear
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@lilac pier what

viscid thistle
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ok

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I know thatt

lilac pier
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nvm

viscid thistle
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by how is sin(...)cos(...) less than or equal to 2

willow bear
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no

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did you read what i said

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$2\sin(...)\cos(...) \leq 2$

obsidian monolithBOT
willow bear
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$2\sin(...)\cos(...) \leq 2 \times 1 \times 1$

obsidian monolithBOT
viscid thistle
#

OH SHIT

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2 times 1

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times 1

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ARITHMATIC

willow bear
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ftr, it doesn't look like this is gonna be enough to find the actual max value

viscid thistle
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what do I do now

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😦

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so I don't do my hw?

willow bear
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i don't see a way to do this without calculus

viscid thistle
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😦

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what if I use sum and dufference formula

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sin(x+2x)

willow bear
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uh what

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you don't have sin(3x)

viscid thistle
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and like sinxcos2x+cosxsin2x

willow bear
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you have sin(x) + sin(2x)

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no

viscid thistle
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and like graph it

willow bear
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you are not starting with sin(x+2x)

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sin(x) + sin(2x) is not the same thing as sin(x + 2x)

viscid thistle
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I know

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wait

willow bear
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starting with sin(3x) is going to be pointless

viscid thistle
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I saw my teacher do sin+cossin=sin(1+cos)

willow bear
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sin(x) + cos(x)sin(x) = sin(x) * (1 + cos(x)) sure

viscid thistle
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why

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is it cause there's no variable

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and it

willow bear
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why what

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$a + ab = a(1+b)$, this is just algebra and has nothing whatsoever to do with trig

obsidian monolithBOT
viscid thistle
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I know

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I'm not stupid I'm just uhh

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Are you finding min/max?

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fuck blame it on the sprite

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yes sir

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Hmm

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@willow bear

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I think knight has a soluuttion

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And I’m assuming you don’t know calculus?

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yyep

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how'd u know ❤️

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Hm

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calculalusssss

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my precalc book is shit

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utter garbage

lilac pier
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Well

viscid thistle
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no I'm a human

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not a well

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lol best math teachers

willow bear
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...

lilac pier
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Since y=sinx and y=sin2x have a phase difference, we can't add 1+1.

willow bear
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what

viscid thistle
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explaining calculus without calculus

willow bear
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they don't have a fucking phase difference

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they're not phase-shifted wrt one another sup

viscid thistle
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0.o oh damn

lilac pier
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They are?

willow bear
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no they're not

viscid thistle
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theyy dont

willow bear
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they're fucking sin(x) and sin(2x)

viscid thistle
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even i know that

willow bear
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they have fucking DIFFERENT FREQUENCIES

viscid thistle
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OH DAMN

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U PULLED OUT THE F WORD

lilac pier
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oh right I meant that then

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no it's okay she is the master

willow bear
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sup just don't spew more nonsense aobut things you know nothing about

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just stop

viscid thistle
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0.o

lilac pier
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Yeah my bad

viscid thistle
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What’s the point of analyzing them separately

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so do what do I do now

willow bear
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honestly i don't know

viscid thistle
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😢

willow bear
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this problem is inaccessible at your level. i really doubt that there's a way around it.

viscid thistle
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u think it wants me to graph it and wright down what I see

willow bear
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here i can even give the exact answer

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which i guarantee you is impossible to arrive at w/o calculus

viscid thistle
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1.76 or something

willow bear
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it's 1.76ish yes but unless you're asked to find that value to two decimal places this won't do

viscid thistle
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How would I do it with calculus>

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??*

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Do you know anything about derivatives

willow bear
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he does not

viscid thistle
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its the slope or something

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like y=5x has a derivative of 5

willow bear
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i'm not about to give a calculus 1 lecture in ten minutes

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it's more than just "the slope or something"

viscid thistle
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I mean real genius can explain anyyhting in 10mins

willow bear
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no

viscid thistle
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I don’t think there’s a point for you to understand the calculus right now

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😦

willow bear
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you can't explain a phd thesis in 10 minutes in its entirety to a five year old

viscid thistle
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I'm 16

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rUdE XD

willow bear
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i was not referring to you specifically

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nor was i likening myself to a phd, which i'm not

viscid thistle
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yes ma'am

willow bear
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the exact answer is $\frac{(3 + \sqrt{33})\sqrt{30 + 2\sqrt{33}}}{32}$, and you'd find that by setting $\dv{x} (\sin(x) + \sin(2x)) = 0$ and evaluating $\sin(x) + \sin(2x)$ at those values of $x$.

obsidian monolithBOT
viscid thistle
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The metaphor is you can’t explain something a little more advanced to a beginner without providing more background

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And that background will be given to you in further courses

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my precalc class supposed to be like around half a semester long

willow bear
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uh yeah you were given a calculus problem in a precalc worksheet and you don't have the tools necessary to solve it

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there really is nothing else to be said here lol

viscid thistle
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it's not in a worksheet

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it's in my book

willow bear
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homework assignment

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whatever

viscid thistle
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my book is stupid

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??

willow bear
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idk why anyone would even put that in a precalc book

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¯_(ツ)_/¯

fluid shore
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Uh can you show us the question from the book

viscid thistle
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Precalculus 5th edition

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mathematics for calculus

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65

fluid shore
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,rotate 270

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Wow fk

obsidian monolithBOT
native sequoia
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yeah it has that graph symbol

viscid thistle
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what's that mean

dim jungle
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just say ur pencil wrote it and ur brain agreed

fluid shore
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You gotta graph it to get the maximum and minimum

viscid thistle
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with hand

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or calculator

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Calc

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cause idk hwo to graph this by hand

fluid shore
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Even if it was with a calculator, do it by hand

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It's better for you

viscid thistle
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@willow bear how do i do it by hand

dim jungle
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just draw

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squiggles

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but then

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like rly close

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but then

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make it so that one little box is like 1000 pi

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so they cant say ur wrong

willow bear
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you can't

dim jungle
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its just a lot of squiggles mushedtogether which lookes like ||||

willow bear
#

what does that graph icon next to the question mean

viscid thistle
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Yes but the range really matters with this

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idk

fluid shore
#

It just means you have to get it by graphing it. Typically, it means you have to use some gdc

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Looking at the rest of the questions, they don't seem to lend themselves to precalc methods. You probably have to use a gdc to graph them and get the maximum

viscid thistle
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Idk

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I think I need to use a graphing calculator

willow bear
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it says it right there

viscid thistle
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0.o

willow bear
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if only you just

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read the paragraph

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titled "Scientific and Graphing Calculators"

viscid thistle
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we just got this book

willow bear
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read it

fluid shore
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:/

viscid thistle
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all of it?

willow bear
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it ain't that much

fluid shore
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That entire conversation above took place for absolutely nothing

willow bear
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unless your reading comprehension only allows you to grapple with about a dozen words at a time

viscid thistle
#

bruh why u roast me like that

fluid shore
#

It's not a roast

viscid thistle
#

kinda is

dim jungle
#

it looks like a thick book

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tho

fluid shore
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Dude

viscid thistle
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it is thick

fluid shore
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If it doesn't apply to you, it's not a roast.

willow bear
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how hard can it be to read ONE (1) paragraph containing PRECISELY the information you need

viscid thistle
#

thicker than me

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I read it now

willow bear
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yeah great

viscid thistle
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I dont wnna read the rest tho

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XD

dim jungle
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bad

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go read

viscid thistle
#

these symbols are trippy

willow bear
#

can you now

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tell me what the graph icon means

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based on what you read

viscid thistle
#

use a graphing calculator

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those are expensive

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😢

dim jungle
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online

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graphing calc

viscid thistle
#

Desmos is great

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I mean I have one

fluid shore
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I think some people use desmos or something

willow bear
#

a graphing calculator or a computer with graphing software.

viscid thistle
#

I'm just saying it's expensive

willow bear
#

READING COMPREHENSION BRUH

viscid thistle
#

If you have one use it to your advantage

dim jungle
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this man has the biggest brain

viscid thistle
#

I did better on the math sat part

willow bear
#

YA GOTTA GET SOME AT SIXTEEN YEARS OF AGE DONTCHA THINK

fluid shore
#

I can agree with you: they're really expensive and very dumb

viscid thistle
#

english is hard

dim jungle
#

yeah english is hard

viscid thistle
#

ann r u 30?

fluid shore
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Ann, he didn't say he couldn't use an online software.

willow bear
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20

viscid thistle
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0.o do u atten uni

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for math

willow bear
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yes

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i'm in my third year

viscid thistle
#

is it a top uni?

willow bear
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i think so

viscid thistle
#

harvard?

willow bear
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no

viscid thistle
#

yale?

willow bear
#

i'm not in the US

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nor in an english-speaking country

viscid thistle
#

Vietnam?

willow bear
#

lmao

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but no

viscid thistle
#

is it in asai?

willow bear
#

no

viscid thistle
#

Asia*

dim jungle
#

is it in europe

viscid thistle
#

uhh poland?

willow bear
#

closer but no

viscid thistle
#

hungary?

willow bear
#

no

viscid thistle
#

Germany?

willow bear
#

saint petersburg state university, in russia

fluid shore
#

Lmao

viscid thistle
#

RUSKY

#

Privet moy drug

willow bear
#

....

dim jungle
#

very nice

viscid thistle
#

Piveat

#

Kak dela

dim jungle
#

how much work

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do u get

willow bear
#

"piveat"

viscid thistle
#

moyo emya jager

dim jungle
#

like how many hours a day

viscid thistle
#

priveat*

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XD

dim jungle
#

hw

willow bear
#

ok uh

dim jungle
#

avg

viscid thistle
#

Skoko vremine u vas?

fluid shore
#

Take this to chill

willow bear
#

can we like not do poorly transcribed russian

viscid thistle
#

I like russia

willow bear
#

also yeah

viscid thistle
#

it has snow 😄

fluid shore
#

Take this conversation to chill, guys

willow bear
#

this is #chill conversation now

dim jungle
#

im guessing like 3 hours

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a day?

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hw?

viscid thistle
#

I can speak, can’t read/write );

dim jungle
#

no thats too little

viscid thistle
#

lol

fluid shore
#

TAKE THIS CONVERSATION TO CHILL

viscid thistle
#

ttatt wont work

dim jungle
#

maybe 5 hours?

viscid thistle
#

OK LEMME BRING IT BACK TO MATH

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what's the arc length of the curve in p

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p is russia

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cause priveat

dim jungle
#

no ones going to respond

viscid thistle
#

What

fluid shore
#

TAKE THIS CONVERSATION TO CHILL

viscid thistle
#

and russia in russain starts with p

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Россия

fluid shore
#

Stop. Others might want to ask questions here. Go to #chill

native sequoia
#

pootis

summer monolith
fluid shore
#

Nope

#

$-ct = \ln(\frac{B}{cD}) \implies t = -\frac{1}{c} \cdot \ln(\frac{B}{cD}) = \frac{1}{c} \cdot \ln(\frac{cD}{B})$

obsidian monolithBOT
fluid shore
#

There we go

#

basically, the stuff inside the logarithm was flipped

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@summer monolith

summer monolith
#

ln(B/cD)=-ln(cD/B) ?

languid crane
#

log properties

fluid shore
#

mmmh that was the property that was used

summer monolith
#

log properties
Can't see this one in the list

uncut mulch
#

$-\ln(x) = \ln(x^{-1}) = \ln ( \frac 1x )$

obsidian monolithBOT
uncut mulch
#

application of power rule

fluid shore
#

what do you mean you 'can't see this one in the list'

#

you don't just have a piece of paper listing all the laws that you've encountered so that you can just pull one or two laws from it when you need them

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try to actually follow the logic of the argument and you'll live a happier life

summer monolith
languid crane
#

its clearly there

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log_a (x^n) = n log_a(x)

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no?

fluid shore
#

NO, THIS IS WHAT I MEAN

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DO NOT SIMPLY HAVE A LIST THAT YOU'RE TAKING FORMULAS OFF OF.

summer monolith
#

Is this an imperative or a statement?

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And why not?

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It makes life easier

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Wew
I didn't realize that 1/(a/b)=b/a

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Not sure though. I need to check again.

fluid shore
#

??????????

summer monolith
#

Nevermind
I was just thinking about the derivative of ln(cD/B)

summer monolith
#

Lol
I've just waisted hafl an hour trying to comprehend how c^2De^-ct derives from 1/c*ln(cD/B)

stuck lark
#

$\dv{S}{t}=B-cDe^{-ct}\\\dv[2]{S}{t}=\dv{t}(B-cDe^{-ct})=,?$

obsidian monolithBOT
summer monolith
#

I did realize what was the problem

#

eventually

stuck lark
#

👍🏾

nova dew
#

$\lim_{x\to 1} \frac{x^m - 1}{x^n -1}$ hello I'd appreciate some help

obsidian monolithBOT
nova dew
#

what am I supposed to do exactly

fluid shore
#

Find the limit, if it exists

willow bear
#

one of the few cases where LH makes it possible to avoid having a shitton of different cases

undone pawn
#

wdym different cases?

willow bear
#

natural, integer, rational, arbitrary real

undone pawn
#

ohh ok

pale bison
#

wait you're learning derivative but don't know log rules what

fluid shore
#

?

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The basic idea of a derivative has nothing to do with log rules

pale bison
#

i mean... isn't log a prereq of calc

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oh nvm this is precal, ok

fluid shore
#

I mean, i guess it is but it is not a prerequisite to understanding the basic idea of a derivative or an integral

trim fable
#

how would u do the graph on the right?

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f(g(x))

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how would i fine the points for that?

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or find the equation?

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can anyone help with that

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oof

fluid shore
#

Well, what do you think?

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You're trying to find f(g(x)), where the input is now g(x), rather than x

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What can you do with that?

trim fable
#

oh

#

uh

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idk ;-;

#

I do this?

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is there an easier way tho :c

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well faster*

#

@fluid shore

fluid shore
#

Well, how's that gonna help you here, though?

trim fable
#

oh is it not?

fluid shore
#

When you suggest a method of doing something, you need to consider the reasons for why it's gonna help you.

trim fable
#

uh u can

fluid shore
#

Did i say it wouldn't? I'm asking ya to think through it and see if it does help you.

trim fable
#

find the points for f(g(x))

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then plot them

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using that^

fluid shore
#

Well, you could do that, certainly

#

Since f(g(x)) = 2g(x) + 1 = 2(3x-2) + 1 = 6x - 3, you can also do it that way.

trim fable
#

oh then

#

simplify?

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after making them equal?

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so x-3?

#

@fluid shore

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would be

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f(g(x)) ?

fluid shore
#

No

trim fable
#

oh

fluid shore
#

I just found f(g(x)) for you

trim fable
#

oof

#

oops

#

oh so

#

u plugged g(x) into

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the f(x) equation?

fluid shore
#

Yes

trim fable
#

oh

#

ok

fluid shore
#

Keep in mind, the input has now changed from being x to g(x) instead.

trim fable
#

oh ok

#

so it would be 6x-3?

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OH yay

#

thats what u got

#

so that would be the function for f(g(x))

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so i could just plot it?

fluid shore
#

What do you think?

trim fable
#

question tho how does this relate to the mapping thing?

#

i think : yes

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but i dont really understand why we do this

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can u explain how they are related or something

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😛

fluid shore
#

What do you mean

trim fable
#

nvm

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lol

#

what is that asking

fluid shore
#

Well, i mean, there's a bit of work that does go into all of this

trim fable
#

ye

#

slope is 6 equation is 6x-3

fluid shore
#

There's a bit of theory so you'll just have to read up on it. Then, you can ask questions if you're confused.

trim fable
#

but what about the next part

#

is that what I just did?

fluid shore
#

Yes

trim fable
#

oh

fluid shore
#

Lol

trim fable
#

and the next thing?

fluid shore
#

That last bit?

trim fable
#

yes

fluid shore
#

They're asking you to compare g(f(x)) with f(g(x))

trim fable
#

question th

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u know when they asked to graph

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was i expected to just do it without

#

solving for it?

fluid shore
#

Well, i think that's what you were meant to do

#

You were supposed to plot points

trim fable
#

ok

#

uh

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for the last bit

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is the answer no

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coz its not the same equation?

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@fluid shore

fluid shore
#

Idk, you tell me

trim fable
#

yes

#

its not

fluid shore
#

Yeap, so if they don't give the same result, they're not the same

trim fable
#

Yay

#

im self teaching myself this

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before school starts which is why im so clueless LOL

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u know whats sad

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i did what u taught me

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i got

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x^2+2x+1

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but sadly i forgot how to Graph quadratics thats super sad

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@fluid shore

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lol

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oh wait

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i can complete the square

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but i think i forgot how to

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rip

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@fluid shore Am i doing it right so far tho?

fluid shore
#

Lmao

trim fable
#

lol

fluid shore
#

f(g(x)) = (g(x))^2 = (x+1)^2

trim fable
#

yes

#

i expanded.. oof

#

was i not

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supposed to

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😅

#

lol

fluid shore
#

No, you asked about completing the square

trim fable
#

oh

fluid shore
#

That's the completed square

trim fable
#

thats literally what i

#

started with tho..

fluid shore
#

First of all, graph x^2 and x+1

trim fable
#

i did

fluid shore
#

Then, graph (x+1)^2 by plotting points

trim fable
#

ok

fluid shore
#

Legit, if you're not confident about doing it straight away, just plot points

#

There's nothing harmful about that

trim fable
#

okk

#

hmm

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is it the same graph

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no right?

#

wait tbh for

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i think they are does it count if

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actually nvm

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they aren't lol

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right?

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@fluid shore

fluid shore
#

What

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You mean is (x+1)^2 the same as x^2

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No they are not the same, my dear

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But

#

They do look the same cos they're both parabolas

trim fable
#

yes

#

lol

#

ok so

#

i did this part on my own

#

and other points I got were

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using g(1) point (1,4)
using g(2) point (2,9)
using g(-1) point (-1,0)

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are those right

#

@fluid shore

fluid shore
#

Do you expect me to do the calculations in my head?

trim fable
#

yeahh 😛

#

ur smartt lol

fluid shore
#

Check the calculations you have done. If they're correct, then they're correct. If they're not, redo them.

#

Then, plot the points.

trim fable
#

uh how do i check if they are

#

oh

#

plug them

fluid shore
#

Did you follow the steps given correctly? Did you find every value that you need to calculate correctly?

trim fable
#

into the equation

#

yes

#

i think im right

fluid shore
#

Yes.

trim fable
#

waitttt

#

x^2 is equal to

#

(x+1)^2

#

its the same graph

#

but translated

#

so they are equal? @fluid shore

fluid shore
#

???????????????

#

They look the same, yes

#

As i said before, they're both parabolas

pale bison
#

they're not equal

trim fable
#

why?

fluid shore
#

Is 4^2 = 3^2?

trim fable
#

but its the same

#

graph just

#

translated?

#

soo

#

does that

#

not count?

pale bison
#

shifted

trim fable
#

yes

fluid shore
#

Yes, they look the same. They're both parabolas

pale bison
#

Is 4^2 = 3^2?
answer this

trim fable
#

lol

#

16=9

#

yes

#

jk

#

ok

#

😛

fluid shore
#

Okay, so have you solved the problem?

trim fable
#

yup

#

😄

fluid shore
#

Good.

trim fable
#

yes

#

ima teach myself lesson 2 now

#

LOL

pale bison
#

have fun and feel free to ask questions

trim fable
#

I prob will

#

ask

#

LOL

#

i self teaching which does't help when ur just answering questions from class notes which u would do with the teacher but

#

annywayssss

#

i wanna get ahead so i can stay in winter break mode when school starts LOL

#

coz ill be done the work 😄

fluid shore
#

ill be done the work

#

Consider taking some English classes as well 🙂

#

Prank

pale bison
#

ah yes

#

lmao

trim fable
#

what do u mean

#

i have english next semester sooooo

fluid shore
#

Are you in high school?

trim fable
#

yeah

#

im in grade 12

#

lol

pale bison
#

cool beans

trim fable
#

I need a uniiiiiiiiii

#

ahhhhh

#

im scared tho

#

all my marks have been dropping

#

;c

pale bison
#

like unicycle? everyone is scared of a unicycle, you're not alone

#

jokes aside, just have a positive attitude and roll with it know what i mean

trim fable
#

LOL

#

nah I mean university 😛

pale bison
#

yeah ik

trim fable
#

ik 😛

fluid shore
#

What do you want to study in uni?

trim fable
#

Engineering

#

or computer science

#

i would honestly just do math but apparently u cant really do much with just math so rip

#

are u guys american?

fluid shore
#

I'm Singaporean. I believe Publius is American.

pale bison
#

yes

trim fable
#

ur from Singapore?

#

oh ok

#

OK TIME FOR THE NEXT LESSON

#

😛

#

ok then i guess im

#

doing that

#

isn't that what we were doing

#

@fluid shore

#

making them equal?

arctic mantle
#

Halp <@&286206848099549185>

trim fable
#

?

#

oh that

#

i think i forgot how to rip

#

;-;

#

@pale bison uh u know how

#

does that mean

pale bison
trim fable
#

for the first one

#

oh

#

what did i do ;-;

pale bison
#

that's meant for MrBioFex

trim fable
#

oh ok

#

(x+3) (x^2-12) for i
then would ii be (x^2-12) (x+3)?

clever inlet
#

How'd you get that

trim fable
#

f(x) x g(x)

clever inlet
#

It's composition

#

Not multiplication

pale bison
#

they're not multiplying

#

the key word is composition like Kangaroux said

trim fable
#

oh

#

idk then ;c

#

self teachings so hard ahh

pale bison
#

okay

#

i'll give you one quick example

trim fable
#

OH OK

#

yay

pale bison
#

say you have $f(x)=x^2+2x$ and $g(x) = \sqrt{x}$

obsidian monolithBOT
trim fable
#

ok

#

😮

pale bison
#

then, when you say f compose g, what that means is that:

take the function g(x), and plug it into f(x)

so, you have f(g(x))

trim fable
#

oh

#

wait

#

so the circle means

#

composite?

pale bison
#

so, whenever you see x in the function f(x), you replace it with g(x)

#

yes, that circle

#

exactly

trim fable
#

oh..

#

that makes so much sense

#

i thought the circle was

#

multiplication coz sometimes a dot represents that

pale bison
#

multiplication is mostly likely a dot

trim fable
#

ye

pale bison
#

only losers use X

trim fable
#

lol

#

😛

fleet yew
#

Its not X

trim fable
#

lol

pale bison
fleet yew
#

Its ×

trim fable
#

lol

pale bison
#

ok

#

ok you have a macro or greek letter keyboard or whatever

fleet yew
#

I personally like the cross notation

#

It reflects the true meaning of multiplication

trim fable
#

hmm

#

i use both

#

depends on my mood

#

lol

pale bison
#

the true meaning of multiplication is to expand it to addition

fleet yew
#

To multiply a and b means to find the area of a rectangle with side lengths a and b

trim fable
#

question

fleet yew
#

Kind of like "crossing" the side lengths if you will

trim fable
#

so from the notes i sent

#

f composite of g(x)

#

for a is

#

x^2 -12 +3 ?

fleet yew
#

x^2-12+3=x^2-9

trim fable
#

x+3
(x^2-12) +3
x^2 -12+3

#

?

fleet yew
#

Yes

#

Combine like terms

trim fable
#

oh

#

oops

#

lol

#

didn't realize that

#

thankss

fleet yew
#

Lol this is what precalc is nowadays?

trim fable
#

then

#

oh this is

#

unit 9

#

last one

fleet yew
#

Im just old ig

trim fable
#

oh

fleet yew
#

I dont remember precalc

#

I just recall it being way harder

trim fable
#

lol

fluid shore
#

It matters not how hard it is. It only matters that you understand what's being presented.

trim fable
#

tho I HAVE TIME

#

wellllllllll

#

uniiiii caressssssss

#

about the markkkkk

#

;c

#

which hurts but its fine..

pale bison
#

this pre uni section of discord is really mixed up

trim fable
#

what do u mean?

fluid shore
#

Yer mum was mixed up

#

PRANK

#

RELAX

#

MEMES

#

CHILL

#

SHHHHh

trim fable
#

huh

pale bison
#

well, because they're all "basic" and i don't think it matters that much that we have four different channels for it

trim fable
#

so g composite of f is x^2 +6x -3?

pale bison
#

@fluid shore thanks good meme

#

i'm reporting you to the mod

#

enjoy your ban

fluid shore
#

Nah 4 different channels is so that we can help different people with different questions

#

😦

pale bison
#

jk

trim fable
#

hey so was i right

#

AHH

pale bison
#

which one are you talking about?

trim fable
#

a

#

for ii

#

and iii is just saying if both equations were equal right?

#

so no?

pale bison
#

yes you are correct that "so g composite of f is x^2 +6x -3" for a)

trim fable
#

OK

#

yay

#

also was that what iii wants^^

pale bison
#

i think there's a typo

trim fable
#

ye

#

same

#

do they mean

#

f o g(x) = g o f(x)?

pale bison
#

yees

trim fable
#

answer = no

#

😛 ?

#

right 😛

pale bison
#

what's your reasoning?

trim fable
#

coz they aren't the

#

same equation

pale bison
#

hmm

#

if i have f(x) = x+1 and g(x)=x-1
then f compose g and g compose f are the same, despite them being different

trim fable
#

huh

pale bison
#

so them being different is NOT enough to finish the problem

trim fable
#

im so confused now ;-;

pale bison
#

do the dirty work and calculate it

trim fable
#

how

pale bison
#

just like how you did in question i

trim fable
#

oh..

pale bison
#

do f compose g, then do g compose f

#

then compare them

trim fable
#

i did tho

pale bison
#

okay, then good, that's the right way to do it

trim fable
#

x^2-9 = x^2+6x-3

#

and they aren't

#

equal

pale bison
#

where did those equations came from?

trim fable
#

f composite of g(x)

#

and then g composite of f(x)

#

i jus used my answers for i and ii for iii

#

can I not?

pale bison
#

ohh

#

i read the question wrong

#

i thought i is for a)

#

ii is for b

#

and iii is for c

#

my bad, yes

#

you're right

trim fable
#

lol

#

ok

#

so i just look if

#

they are the same

pale bison
#

yeah

trim fable
#

and say yes or no

#

ok lol

#

u really made that

#

complicated thats

#

very funny 😛

#

lol

pale bison
#

... okay

trim fable
#

LOL

#

aww sorry

#

did i hurt ur feelings ;-;

pale bison
#

my bad

#

no you didn't i have no feelings

trim fable
#

question are u in uni

#

aww why not

pale bison
#

yes

trim fable
#

oh wow

#

what year

#

😮

pale bison
#

2nd

trim fable
#

oh 😮

#

cool

#

hows

#

that going

pale bison
#

so far so good
but then i compare my self to people here and i feel like i'm a big dumb

trim fable
#

oh rip

#

honestly idk if im dumb or smart

#

coz im good at math but lol sometimes Im just

#

very stupid

pale bison
#

peepoShrug always happens, to anyone

trim fable
#

my marks dont show that im good at it ;-;

#

it did before

#

which is why i dont find marks a fair way to

#

judge someones intelligence

#

coz i was at a 87 now look im at a 77

#

CAUSE: STRESS DURING TESTS

pale bison
#

well, test scores don't measure intelligences first of all

trim fable
#

well averages?

#

coz i think i should be at a 87 tbh

#

maybe even 90

pale bison
#

it measures how well you understood the concepts (at least it tries to)

trim fable
#

i could have gotten there

#

if i didn't mess up so bad

pale bison
#

and that corresponds to how much you practice

#

more practice = higher score

trim fable
#

one test brought me down 7%

pale bison
#

so just work on it

trim fable
#

then i dropped 1 each time lol

#

but i do tryyyy

#

i do practice i just

#

stress out during tests and i blank out coz all thats in my mind is u gotta do this if u wanna go to uni and then

#

i panic when i dont get something then my confidence goes ⬇️

pale bison
#

well yeah, that happens

trim fable
#

but does uni care

#

NOPE

#

im scared ;c

#

lol

#

hey so for

#

b

#

i would be x+2

#

and ii would be x

#

right?

willow bear
#

how did you get x+2 in b/i

trim fable
#

oh ok so

#

(square root of x+1)^2 +1

#

the square cancels the square root

#

so then

#

x+1+1

#

which equals x+2

#

right?

willow bear
#

alright first off

#

don't write square root like that

#

second, $g(x)$ is not $\sqrt{x+1}$

trim fable
#

like what?

obsidian monolithBOT
trim fable
#

it was -1 actually

#

oh rip

#

OOPS

willow bear
#

third, you really should write sqrt(x-1)

trim fable
#

oh ok

willow bear
#

f(g(x)) = (sqrt(x-1))^2 + 1

trim fable
#

wellits hard to say what u wanna say

willow bear
#

with the parentheses

trim fable
#

for math on

#

messages

#

its right on my paper

#

LOL

#

oh btw the answer should be x

#

these equations are equal YAY

willow bear
#

b/ii is not x, ftr

trim fable
#

oh rip

#

i plugged in +1.. again..

#

🤦‍♀️

#

would it be

#

x- sqrt(2)

#

@willow bear

willow bear
#

would what be x - sqrt(2)?

trim fable
#

the answer for b/ii

willow bear
#

no

trim fable
#

oof

#

what did i do wrong ;-;

willow bear
#

well show your work

trim fable
#

ok

willow bear
#

on paper maybe

#

so that the communication mishap doesn't happen again

trim fable
#

sqrt(x-1)
sqrt(x^2-1-1)
sqrt(x^2-2)
cancelled square with square root for x which gave me:
x- sqrt(2)

willow bear
#

okay so

#

first off

#

f(x) is not x^2 - 1

#

and second

#

not only is sqrt(x^2) not equal to x in general, you also pulled a fucking freshman's dream

trim fable
#

oooooooof

#

OMG

#

why am i copying these wrong

#

LOL

#

wait no

#

wait ye

#

rip

#

hey so i was

#

right before

#

it was x?

willow bear
#

no you weren't

trim fable
#

sqrt(x^2)

#

is x

willow bear
#

$\sqrt{x^2} = x$ is not true in general!

obsidian monolithBOT
trim fable
#

but the

#

square was

#

outside

#

oh no

#

nvm

#

rip

#

thanks

willow bear
#

if $x = -5$, then what is $\sqrt{x^2}$?

obsidian monolithBOT
trim fable
#

5

willow bear
#

exactly.

trim fable
#

true

#

ok

#

my bad i thought it was outside coz

#

idk

#

lol

#

no wait i messed up

#

i guess i just did it without actually considering where the square was

#

so the final answer is just sqrt(x^2)

#

or i can fo

#

cant i do

#

x^(2 x 1/2)

#

and i get x^(2/2)

#

which is just x?

#

@willow bear

willow bear
#

no! that only works if x is positive! which you cannot assume!

trim fable
#

oh

willow bear
#

you literally just demonstrated that $\sqrt{x^2}=x$ is false in general, since for example it is false for $x=-5$ !

obsidian monolithBOT
trim fable
#

lol

#

oops

willow bear
#

think! think about the things you say!

trim fable
#

;-;

#

sorry ;-;

#

so the answer is just

#

sqrt(x^2)

willow bear
#

sqrt(x^2) can be simplified.

#

not to x, but to something else.

trim fable
#

to?

#

oh

#

(x^2)^1/2 ?

willow bear
#

no

#

|x|

trim fable
#

oh..?

#

how so

pale bison
#

$x^{2^\frac{1}{2}}=\sqrt{x^2}=|x|$

obsidian monolithBOT
trim fable
#

but how is it the

#

absolute value?

pale bison
#

well

#

take -4 for example

trim fable
#

ok

pale bison
#

square that number

trim fable
#

oh..

#

i get it ok

pale bison
#

neat

trim fable
#

u will always square the

#

number so

uncut mulch
#

bad tex

trim fable
#

the - will always become

#

a positive right?

#

so then u dont have to deal with

#

square rooting a negative number?

#

which is why it will be

#

absolute?

#

coz then u get the same number

pale bison
#

umm

trim fable
#

but positive since u square then cancel that with the square root

pale bison
#

square root of a negative number is called imagenary

trim fable
#

but the square will convert to a positive then undo

#

yes

#

ik