#precalculus

1 messages · Page 189 of 1

trim fable
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(144 square root 3)/16

uncut mulch
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could've been simplified more easily without multiplying it out

trim fable
#

then 9square root 3)

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ik

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3/2 would have been

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simpler

uncut mulch
#

can you continue from
log_3( 9sqrt(3))

trim fable
#

uh

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idk what to do

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with the root

uncut mulch
#

try writing it as a power of 3

trim fable
#

3^ 1/2

uncut mulch
#

um do it separately

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9 = 3 ^ what

trim fable
#

2

uncut mulch
#

sqrt(3) = 3^ what?

trim fable
#

1/2

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now add exponentsss

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so

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5/2

uncut mulch
#

yeh,
9sqrt(3) = 3^(5/2)

trim fable
#

yay

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thats the answer

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5/2!

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coz

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5/2 log 3 (3)

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5/2 x 1

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= 5/2

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yay

uncut mulch
#

yep !

trim fable
#

yay

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do u think

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im good at this or pretty bad?

uncut mulch
#

getting better.

trim fable
#

lol

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so not good yet?

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lol

uncut mulch
#

needs more practice

trim fable
#

yeah

trim fable
#

heyy

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@uncut mulch how would u do this wait uh

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6 d.)

uncut mulch
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6sqrt(2) = 3 * 2 sqrt (2)

viscid thistle
#

how would I prove the existence of an inverse implies a function is injective

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and the other way

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$\forall b \in B: \exists ! a\in A: fa=b \Leftrightarrow \exists f^{-1}: B \to A$.

obsidian monolithBOT
viscid thistle
#

sorry mental blank

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$\exists g : B \to A: g \circ f = i_A \wedge f \circ g = i_B \implies \forall b \in B: \exists! a\in A: fa=b$ is ez

obsidian monolithBOT
viscid thistle
#

because if the composition of f and g is injective, f and g are injections

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could anyone give me a hint about the other way

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<@&286206848099549185> has been > 15 mins since q was posted

uneven pagoda
#

Hi guys, I'm having a lot of trouble verifying this problem. I'm trying to get one side to match the other. I've tried turning tangents on the left side into sin/cos and finding the GCF but keep getting stuck. Not sure what to do.

patent beacon
#

cot(x) = 1/tan(x)

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Should be immediate after multiplying top and bottom by tan(x)tan(y)

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Converting right to left I mean

uneven pagoda
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so turning the cotangents into 1/tan and than multiplying by tanxtany?

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then*

patent beacon
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Ya

uneven pagoda
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What do I do with the -1 on the cotangent side? Does that turn into -(tanxtany)? The rest is good though

patent beacon
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Yeah it does

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Seeing as that's what you have on the left, that's exactly what you want

uneven pagoda
#

Thank you for you help hype

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your*

trim fable
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hi @patent beacon

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😛

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how are uuuu

candid onyx
willow bear
candid onyx
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Lol I forgot to add it in at first

willow bear
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anyway ok first off

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tan(2x) is 90°-periodic

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and second

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solutions (in degrees) to one decimal

candid onyx
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What do you mean 90 degrees periodic?

willow bear
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tan(2(x+90°)) = tan(2x)

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solutions repeat every 90° rather than every 180° as with tan(1x)

candid onyx
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So add 90 and 180 instead of 180 and 360?

willow bear
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no you add multiples of 90°

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so 270° and 360° too

candid onyx
#

Ok I see now

topaz fox
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is log(n^3 + 6n^2) => log(n^3) + log(6n^2)
?

stuck lark
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no, but log(n^3*6n^2) = log(n^3) + log(6n^2)

valid violet
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numbers don't imply numbers

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you don't say 3 => 6 -3

fluid shore
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Implications are used between two propositions.

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Numbers are not propositions

viscid thistle
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maybe they meant greater-than-or-equal-to?

fluid shore
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Eh, maybe?

valid violet
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Oh

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That would usually be >=

fluid shore
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Maybe they don't know the convention?

valid violet
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"Equal to or greater than" isn't wrong but peopke dont say it

fluid shore
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To be fair, I didn't even know that != means 'not equal' lel

valid violet
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I think it's more likely they were misusing implication

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Well that's borrowed from computer languages, not math

viscid thistle
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Anyone online?

gentle vigil
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@viscid thistle which sub-question are you finding difficult?

viscid thistle
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Making a mapping formula so that I can graph the equation

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@gentle vigil

gentle vigil
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Firstly, you did correct to notice that it is a decay function. Still you have drawn growth

valid violet
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Don't they say the formula in the first line

gentle vigil
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@valid violet precisely.

viscid thistle
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What I drew was the original equation of3^x

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Oh ok I'll erase that

gentle vigil
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You should draw 3^{-x}

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Then you can shift it

viscid thistle
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Thanks, I'm still confused about the ha and vs and all that

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HS and VS

gentle vigil
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What do you mean by HS and VS?

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Oh you mean shift

valid violet
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Horizontal and vertical something?

viscid thistle
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Horisontal stretch and vertical stretch

gentle vigil
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Oh okay

viscid thistle
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Then there are also horisontal/vertical translations

gentle vigil
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Yes

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I don't think you can precisely show stretch in a graph paper unless you put many points and sketch it

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So you should be able to take care of translations mainly.

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For that, you have to find intercepts, asymptotes

viscid thistle
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No he wants the final graph of this though. I added my own graph for my own reference for help

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But they're stretches I just don't know what the exact values are

gentle vigil
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Inverse of coefficient of x tells how much the graph is stretched

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1/2 in this example

viscid thistle
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Oh I see

gentle vigil
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Similarly it isn't stretched in y

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Or stretch in y is 1

viscid thistle
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So since there is a 2 that is made to 1/2?

gentle vigil
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For example, graph of e^x reaches value e at x=1. But graph of e^{2x} reaches value e at x=1/2. So it is compressed in a way.

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Or stretched by 1/2

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Like this

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Or, compare e^{x/2}

valid violet
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Ask yourself

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The point (x,y) on the unstretched curve

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Corresponds to (?,?) On the stretched curve?

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That's how i think of it

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If that confuses you ignore it

viscid thistle
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Ok

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Is the stretch for my graph at 1/2?

gentle vigil
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If your original graph is exp(-x), yes.

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But if you are drawing exp(x). There is a negative stretch as well

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Which means, graph is flipped

viscid thistle
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Ok I will apply the neg but what about a value of 2?

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I'm sorry I'm taking your time, I've been working on this for a while now

gentle vigil
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Because of that 2, the graph will be squeezed by half

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Can you draw 3^{-x}?

valid violet
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We can leave whenever we want, you're not keeping osc here :)

gentle vigil
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Hahah

viscid thistle
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Thanks

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3^-x is decaying and has a hs of 1

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And a
Ry

gentle vigil
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So from 3^{-x} to 3^{-(x-1)}, how would you proceed?

viscid thistle
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Hmm

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One sec

gentle vigil
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Sure

viscid thistle
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Has an Ry a HT of 1 and no HS

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With a base of 3

gentle vigil
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Yes

viscid thistle
gentle vigil
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Hpw would you go from 3^{-(x-1)} to 3^{-2(x-1)}

valid violet
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What's ry?

viscid thistle
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Reflection in the y axis

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It would have an HS of 1/2

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^

gentle vigil
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So can you draw it?

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@viscid thistle I edited the original text. So there won't be any ry

viscid thistle
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Ok

gentle vigil
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Please send the plots if possible so I can understand that you are following it

viscid thistle
#

Ok I need to get graphing paper one second

gentle vigil
#

Rough sketches will work

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Also, now that I know your terminology, I understand what you have written with pencil on your paper and it looks correct.

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You can draw final graph with that information.

viscid thistle
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Ok

gentle vigil
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3^2 = 9

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Otherwise it seems fine

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So now you have to do a -5 VT

viscid thistle
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Also I put it into a graphing calculator and got a y-intercept of 4 but I'm getting a y-incept of 3

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@gentle vigil

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Btw thanks for all of your help!

gentle vigil
#

How are you getting 3?

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What procedure are you following?

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@viscid thistle you are welcome!

viscid thistle
gentle vigil
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Again, 3^2 = 9, not 8

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@viscid thistle

viscid thistle
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Isnt it 2^3?

gentle vigil
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You have 3 as the base, not 2

viscid thistle
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Oh I see

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Lol thonk

gentle vigil
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So now you got y intercept=4

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😅

viscid thistle
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Yup. I thought everything was to the power of 3

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I can guarantee that I won't forget that mistake on a test

gentle vigil
#

I hope you do well!

viscid thistle
#

Tysm! @gentle vigil

gentle vigil
#

You're welcome!

jaunty hornet
#

hello, can someone help me ? i have to show that this function is odd

spark lance
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is f(x) equal to that?

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if so, switch the places of x and f(x)

jaunty hornet
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yup

spark lance
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or maybe not

trim fable
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question

jaunty hornet
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i showed that it was not even, but playing with power gives me nothing

trim fable
#

how would u do 1e

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like

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when u simplify 9

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to 3^2

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do u multiply

spark lance
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yeah

trim fable
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2x+1 like 4x+1 or 4x+2

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which?

spark lance
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4x + 2

trim fable
#

oh

jaunty hornet
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@trim fable it like 2^(2x) = 8

trim fable
#

so both terms

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always?

spring thunder
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i mean that's how multiplication works

trim fable
#

ok i got the answer yay

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LOL

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😛

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yeah

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so its like

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2(2x+1)

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u know how sometimes u

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only multiply the first

spark lance
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in what case?

trim fable
#

uh like

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idk but

spark lance
#

you always distribute it

trim fable
#

yeah

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ok

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oh that was 1d yeah

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ok time for e!!

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yay

spring thunder
#

@jaunty hornet what's blocking you ?

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et coucou

trim fable
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i have a question tho

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why is 1c no solution

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is it coz when u solve u get 0?

jaunty hornet
#

bonsoir haha. when i try -f(x) = f(-x), it's just not the same expression

spring thunder
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an exponential is never negative

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montre moi ça

trim fable
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oh

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ok

spark lance
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an exponent can be negative?

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you just take the reciprocal

trim fable
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how would u do

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1g

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oh nvm

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i was looking at a diff question

spring thunder
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i'm talking about the exponential function

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8^x > 0 for any real x that's what i mean

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ofc the exponent could be negative here

jaunty hornet
spring thunder
#

att tu peux pas sortir la puissance comme ça là

trim fable
#

how do u do

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1h

spring thunder
#

tu fais comme si $$-x+\sqrt{1+x^2} = \sqrt{-x+1+x^2}$$

obsidian monolithBOT
jaunty hornet
#

oui bon jui débile

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mais je vois pas du tout comment réarranger les termes

spring thunder
#

ya le petit trick avec les conjugués qui marche bien ici

jaunty hornet
#

je fais apparaitre un quotient ?

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en * par 1 ?

spring thunder
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yes

jaunty hornet
#

j'vais test, merci !

spark lance
#

@trim fable first you simplify the 9 and 27 to 3 to the power of whatever

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I guess you would get 2x/5 = 3

trim fable
#

i got

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wait

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how did u do that so

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what i did was

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3^3x/15=3^3
3x=45
x=15

spark lance
#

9 = 3^2
27 = 3*3

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and when you multiply the 2 by x/5, you actually only multiply the x and do not multiply the 5 by 2

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for example if you multiplied 4 by 1/2, you would get 4/2 and not 4/8

trim fable
#

oh see

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thats what i meant by

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1 term

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oh k

spark lance
#

yeah it's when you're multiplying by a fraction

trim fable
#

yeah

spark lance
#

if it's x(y+z) then you distribute

jaunty hornet
#

le trick du conjugué me mène nulle part je crois, une autre idée ? @spring thunder

trim fable
#

so then u get

spring thunder
#

j'en ai pas d'autre tbh

jaunty hornet
#

yikes

trim fable
#

2x/5=3

spring thunder
#

mais je sais que le conjugué marche

trim fable
#

2x=15?

spring thunder
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je l'ai fait avec ptdr

spark lance
#

yes

trim fable
#

x=15/2?

spark lance
#

yup

jaunty hornet
#

arf bah j'ai pas réussi à l'utiliser pour montrer l'imparité alors

trim fable
#

how about

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3^-3

spring thunder
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$$\frac{(-x+\sqrt{1+x^2})(x+\sqrt{1+x^2})}{x+\sqrt{1+x^2}}$$

obsidian monolithBOT
trim fable
#

for 1/27

spark lance
#

yes, that is correct

jaunty hornet
#

jusque la j'suis d'accord

trim fable
#

the answer is -1/4

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yayy

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ok so

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i had a question

spring thunder
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simplifie le haut

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tu trouves quoi?

trim fable
#

so

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it would be

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15^x-1=15^1

jaunty hornet
#

1

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du coup aaaah

trim fable
#

x-1=1

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x=2

spark lance
#

yeah it's 2

trim fable
#

ok

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wait the answer is

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0 tho

spark lance
#

what was the original problem?

trim fable
#

oh oops

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i wrote it wrong

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lol nvm

jaunty hornet
#

du coup j'suis débile c'est bon, merci ! @spring thunder

spring thunder
#

👌

spark lance
trim fable
#

i think so

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how would u do

#

c

uncut mulch
#

follow their recommendation/instructions

remote citrus
#

i dont think that is right

trim fable
#

really?

remote citrus
#

i think x=(5+2y)/(3y)

trim fable
#

ye @uncut mulch

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but

uncut mulch
#

show your work

trim fable
#

8^x+1=1

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and i need the same base

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so should i

uncut mulch
#

stop right there

trim fable
#

multiply both sides by 8

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oh

uncut mulch
#

you can't multiply into exponents like that

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by same base, they want you to convert that 4 to a base of 2

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THEN you can multiply them together

trim fable
#

oh

#

wait can i do this

#

4^x+1=1/2
2^2x+2=2^-1
2x+2=-1
2x=-3
x=-3/2

uncut mulch
#

parentheses
that works

trim fable
#

ok

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uh

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what abot 2e

uncut mulch
#

factorise 2^(x+2)

trim fable
#

ok

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so make it equal to 0

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then factor

uncut mulch
#

well to be more specific,
factorise 2^(x+2) - 2^x

trim fable
#

ye and u get

uncut mulch
#

how are you getting that?

trim fable
#

nvm

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lol

uncut mulch
#

do those terms have a common factor?

trim fable
#

2

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1^(x+2)-1^x?

uncut mulch
#

just like the last question, you can multiply/divide into/out of expenents like that

trim fable
#

oh

uncut mulch
#

essentially you just implied that a^anything = a

trim fable
#

oh

uncut mulch
#

a^m * a^n = a^(m+n)

trim fable
#

oh

fleet yew
#

can someone name a function with zeros at every integer

valid violet
#

$f(x)\equiv 0$

obsidian monolithBOT
fleet yew
#

preferably something that can be expressed in y= form

atomic zodiac
#

sin pix

#

the above is just y=0

valid violet
#

$y \equiv 0$

obsidian monolithBOT
viscid thistle
fleet yew
#

this is a pointless venture

viscid thistle
#

@viscid thistle I'm trying to figure out what you're doing, but just can't see it

#

either way

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replace 10 with the base?

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basically what you did was just set x = z, then say x = z

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which is true

icy spruce
#

When finding the modulus you do √x^2+y^2 what about when the y is just -i would't that just be -1?

valid violet
#

modulus of 0+1i is sqrt(0^2 + 1^2)

fleet yew
#

modulus is scalar

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no direction

#

it's taking the absolute value of the distance from the origin on the complex plane

proud jetty
#

How do you get the 1.015x?

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1.5/100=0.015

valid violet
#

Are they really modeling a population with a straight line

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That's nonsense

crisp mesa
#

Yes

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Because population growth is always linear

valid violet
proud jetty
#

can ya all help mEH! :C

crisp mesa
#

Well

valid violet
#

Bc millenials cant afford to have kids?

proud jetty
#

just started log and i got quiz tom

crisp mesa
#

Log1?

proud jetty
#

yeet

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will do 2 soon

crisp mesa
#

Well the population is growing

proud jetty
#

100+1.5/100?

crisp mesa
#

And when it grows you have your orginal population 1, Plus the extra population .015

#

Why are you dividing?

proud jetty
#

to get the decimal value? :idk:

crisp mesa
#

Oh

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Well 1.5% is equal to 0.015

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Adding it too 1 gets you 1.015

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And then you just graph the function

proud jetty
#

oh hmm.. orginal population hmm

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ah ic. thx

crisp mesa
#

idk if i really helped tbh

proud jetty
#

bold of them to assume their was population but k

#

yea kinda did lol thx

hoary valley
red tree
#

$\sqrt{\frac{21}{25}}=\frac{\sqrt{21}}5$

obsidian monolithBOT
hoary valley
#

?

viscid thistle
#

thats how math work

hoary valley
viscid thistle
#

yep

hoary valley
#

Great

obsidian monolithBOT
hoary valley
#

cool!

uncut mulch
#

uh... 1/|a|

viscid thistle
#

Yes but I will assume that they will give nice roots and I dont want to be overly confusing to someone who probably isnt comfortable with absolute value

uncut mulch
#

much better to state the conditions otherwise it may cause problems down the line

#

if you were to avoid abs vals, state that for a>0

viscid thistle
#

Well I agree in principle but I do feel that someone who is not comfortable with how a square root works may be confused by too much info

#

I may be wrong on that but I am just a guy on discord, not a teacher

fleet yew
#

Plus/minus is important

viscid thistle
#

I guess teaching early math isnt my calling

#

In any case from the question they had I would be surprised if they deal with roots of anything but natural numbers at this time

torn swift
#

Teaching at their level is also a big deal, so I see no fault in not giving full details right now. They will learn it later down the line, but for now we want to show the concept without getting bogged down in the details.

hybrid charm
#

±

stark willow
#

so i'm wondering how do know if the derivative of a function is positive or negative or sometimes both?
does anyone have a link or table that explains this?
like x^4 is bigger than x^2.
x^2 is bigger than -(x^6)
but if you start having more complicated functions like x^5-e^x-sin(x)........
how would you know the derivative of the function is negative or positive?

fluid shore
#

Well

#

If f(x) is your function

#

Then calculate f'(x) and set f'(x) < 0 or f'(x) > 0, depending on what you're trying to calculate.

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Then, solve the inequality.

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Sometimes, it's hard to solve the inequality, though. So, you can draw a diagram or a graph and just look at its behaviour to find out where it is negative and where it is positive.

stark willow
#

thank you.

glad shadow
#

Need urgent help guys

cursive river
#

ok whats the question

fading token
heady jewel
#

wow wulfgar is a mathematician

cursive river
#

Umm ok?

fluid shore
#

Lel, @glad shadow you needed urgent help but it’s been about 3 hours.

valid violet
#

@heady jewel he didn't really come across as a mathematician in the books @cursive river

cursive river
#

I dont understand the reference FeelsSpecialMan

valid violet
#

Oh, he's a character in the Legend of Drizzt series by R A Salvatore

#

Wulfgar, son of Beornegar, of the tribe of the elk

cursive river
#

Oh right lol, I get told my name is in multiple things but I actually just made the name up when I was a kid

heady jewel
#

no lol

#

just skyrim

#

high hrothgar

valid violet
#

Skyrim npc is probably named after Salvatore, i took it as a little easter egg

fluid shore
#

Oh Drizzt’ Do’Urden was it?

#

The drow adventurer?

valid violet
#

Yes

fluid shore
#

Oof noice noice

gloomy crow
#

real quick, how do slant asymptotes work?

vivid cedar
#

by dividing numerator by denominator

viscid thistle
#

Hello

#

How do I get what n is 417?

vivid cedar
#

isnt it just 17 + 10(417 - 1)?

viscid thistle
#

Let's see

#

No...

fluid shore
#

No lmao

#

First term is 417 = 17 + 400 = 17 +20*20

viscid thistle
#

So 417 = A_20

fluid shore
#

Idk, you tell me

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Wait fuck haiz

viscid thistle
#

No

vivid cedar
#

oh i read it wrong

#

thought it said the 417th term

fluid shore
#

I changed it

#

Lol

#

417 = 17 + 20*20

#

^

viscid thistle
#

Seem very random

#

What's the logic behind it?

fluid shore
#

?? I mean, i just noticed that the terms generally consist of multiples of 10 + 17

#

So actually, we can write it as:

417 = 17 + 10*40

viscid thistle
#

417= 17 +10 ( 41-1)

Makes more sense

#

Yeeahh

fluid shore
#

Ye

viscid thistle
#

Thanks

fluid shore
#

You can simplify it however you like lol. It’s trivial anyways

viscid thistle
#

The formula should generate the entire series

fluid shore
#

Mmmh yea

prisma prairie
#

im having trouble finding the inverse of this

#

$x-\frac{1}{2}=\frac{1}{y^2}$ I got to this step dont know what to do from here

obsidian monolithBOT
valid violet
#

Combine the LHS into one fraction

prisma prairie
#

$\frac{2x-1}{2}=\frac{1}{y^2}$ okay

obsidian monolithBOT
spring thunder
#

that's very invertible

prisma prairie
#

huh

#

not sure what to do with RHS

valid violet
#

What can you do to both sides

#

To get one step closer to y = something

prisma prairie
#

square root

valid violet
#

Well, i wouldn't do that quite yet

prisma prairie
#

hmm

valid violet
#

Hint:

prisma prairie
#

can i cross multiply

#

LOL that pic

valid violet
#

It's a hint

#

What's the dude doing

prisma prairie
#

a flip

valid violet
#

Ooh

prisma prairie
#

idk

valid violet
#

Is he now

#

I think so

#

I think you're right

prisma prairie
#

would making 1/y^2 into y^-2 help?

#

i dont know see the hint

#

lol

valid violet
#

Flip both sides

prisma prairie
#

wait why

valid violet
#

Try it and you'll see why

prisma prairie
#

ok

#

what property is this

#

i didn't know you just switch fractions like that

#

oh nvm

#

ok thx

#

i got it

valid violet
#

The operation is

#

Raising both sides to the power -1

prisma prairie
#

ohh

#

i see

valid violet
#

But more generally

#

If two things are equal

#

You can treat them.the same

#

That's not worded very well

viscid thistle
#

Hey guys, So when I find the angle between two vectors,
if the angle is 90 degrees it is orthogonal
and if the angle is 0 degrees it is parallel?

restive bridge
#

Nub question.

#

but why usn;t the interval for increase surrounded by brackets?

#

(obv not on inf, but for actual values we know will happen)

#

Oh. I get it.

#

Cause at that exact point that's where it stops increasing/decreasing, right?

valid violet
#

@viscid thistle 0⁰ or 180⁰

#

Depending on if the scalar multiple is +ve or -ve

viscid thistle
#

ok ty

viscid thistle
#

If two vectors are multiplied to each other they then become scalars?

patent beacon
#

You can't multiply vectors

#

If you dot product two vectors, you get a scalar though

viscid thistle
#

@patent beacon so what is |v|^2
Is it considered a scalar product because, the result of getting a magnitude from a vector is a scalar?

patent beacon
#

|v| is a scalar even if v is a vector

#

Well, especially if v is a vector lol

viscid thistle
#

And now that I remember that would make sense because, the definition of a scalar is that it has magnitude only and not direction

patent beacon
#

You can think of a scalar as a real number.
Then vectors as arrows

#

There's a lot of ways to relate these two things

viscid thistle
#

Alright thanks

viscid thistle
#

So the result from a projection is a vector?

patent beacon
#

Yes

viscid thistle
#

Ok cool

harsh cipher
#

Hi

#

do I use properties of logarithm here?

#

a^log base a ^ x = x

#

cant get my head around what's going on with question b 😦

uncut mulch
#

$a^{\log_a x} = x$

obsidian monolithBOT
uncut mulch
#

yes

harsh cipher
#

but how do I change it as exponential form first

#

I don't understand that part :X

spice surge
#

I’m doing practice problems for my class and I am stuck in this question. I can calculate it up myself, but I am trying to figure out how to get it without counting all the way up

willow bear
#

until further information is given, i'm going to assume that all you are given is the first 4 terms \textbf{and nothing else}, which means $a_{14} = 19$

obsidian monolithBOT
spice surge
#

Well by the way it seems, it looks like it divides by two since it goes from 10 to 5, 5 to 5/2 and so on, so I don’t think it can equal 19

uncut mulch
#

@harsh cipher the question is already in the form of that log property

#

work isn't needed and you simply just write ||9||

#

assume it's geometric.
what's the expression for the nth term of a geometric sequence!

#

(in terms of initial a and ratio r)

summer monolith
#

Why not do this like I originally did (I know there are some Xs left to reduce)?

uncut mulch
#

might be a bit less efficient depending on the goal.
also you need to check your signs

viscid thistle
#

its just splitting up the fraction

#

in the original example

#

and also cancelling an X out in the second half

#

$\frac{x^2}{x^4}$ is one result

obsidian monolithBOT
viscid thistle
#

the other i dont want to type in latex on phone

#

that simplified to 1/x^2

uncut mulch
#

-(1+x)(2x) \neq -2x + 2x^3

summer monolith
#

Fug

#

I get -3/x^2

uncut mulch
#

show all steps

#

what you just deleted looked close

summer monolith
prime prawn
#

What relationship must be met so that log_45 [40sqrt(3)] = log_3n [4n]

uncut mulch
#

x(1-2) -2 to -3? how?

summer monolith
#

-1-2=-3

#

oh

uncut mulch
#

x(1-2) to -1 how?

summer monolith
#

my bad

uncut mulch
#

don't divide fractions s like that

summer monolith
#

No. I still don't get it
(1-2)-2=-3
Is it not?

#

like -1-2=-3

prime prawn
#

yeah it is

#

what about it though, the x is only distrivuted to (1-2)

summer monolith
#

Doesn't this x get eliminated by reduction?

prime prawn
#

what reduction?

prime prawn
#

look (1-2)x = -x right

summer monolith
#

with the denominator x^3

prime prawn
#

yes

#

so numerator is -x-2 still

#

cause x is not distributed to the other 2 outside of the parenthesis

#

so you cannot eliminate x from top and bottom

summer monolith
#

I see

#

Then I get (-x-2)/x^3

#

The initial question remains though. How did they split the fraction resulting in two different denominators?

prime prawn
#

much as (x-1)/x = (x/x)-(1/x) = 1-1/x

#

in this case (-x-2)/x^3 = (-x/x^3) + (-2/x^3)

willow bear
#

$\frac{x^2-(1+x)(2x)}{x^4} = \frac{x^2}{x^4} - \frac{2x(1+x)}{x^4}$

obsidian monolithBOT
summer monolith
#

Makes it clear now. Thks.

#

But why did the author choose to leave the final result as a split fraction?

prime prawn
#

preference

summer monolith
#

I thought simplification is the goal
And (-x-2)/x^3 looks much simplier

willow bear
#

But why did the author choose to leave the final result as a split fraction?
w/o context it's impossible to tell

summer monolith
#

There isn't much of a context to be found. Just another practice problem from the book

#

Forget it. Doesn't really matter

summer monolith
stuck lark
#

distribute

summer monolith
#

Thks

steel creek
fluid shore
#

?

steel creek
#

Lol

#

How to solve this

#

I have no idea

#

How to approach the problem

fluid shore
#

What have you tried?

steel creek
#

$(a+b)^3 - 3ab(a+b)$

obsidian monolithBOT
steel creek
#

But

#

a+b

fluid shore
#

Is that the best way to approach this?

steel creek
#

Is problem

#

Is that the best way to approach this?
Idk

#

That's why I'm asking

fluid shore
#

Well

#

$a^3 + b^3 = (a^2 + b^2) \cdot (a+b) -ab \cdot (a+b)$

obsidian monolithBOT
fluid shore
#

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

obsidian monolithBOT
fluid shore
#

Can you use the two equations above? Lmao

steel creek
#

Lol

#

$a+b$ thing

obsidian monolithBOT
steel creek
#

Radicals ewww

fluid shore
#

Radicals are fun, buddy 🙂

steel creek
#

Are you Indian? Lol

fluid shore
#

Maybe, maybe not.

steel creek
#

lol

clear glade
#

Guys why does $2x^2 + 8x + 6/x^2 - 1$ only have one verical asymptote

obsidian monolithBOT
clear glade
#

I thought the bottom can be factored as (x + 1) (x - 1 ) thus a VA at x=1 and x = -1

fluid shore
#

What is a vertical asymptote?

#

??????

#

What bottom?

undone pawn
#

denominator*

fluid shore
#

Fk man, i'm so tired I can't even do English properly. That's how much of a dumbass i am.

undone pawn
#

sleep

#

well @clear glade factor the numerator too

fluid shore
#

Okay, Waterblade, let's get down to business. What bottom you talking about?

clear glade
#

Don't worry, flynn will help me @fluid shore

fluid shore
#

Hold on, is the $\frac{6}{x^2}$ the fraction or the entire polynomial over $x^2$?

obsidian monolithBOT
undone pawn
#

entire

#

$$\frac{2x^2+8x+6}{x^2-1}$$

obsidian monolithBOT
fluid shore
#

Oh wtf

clear glade
#

2(x^2 + 4x + 3) ->2(x+1)(x+3) @undone pawn

undone pawn
#

mm hm

clear glade
#

Is the top

#

So theres a hole at x=1

#

I seeee

undone pawn
#

and denominator is (x-1)(x+1)

clear glade
#

Ahh

#

I see my mistake now

undone pawn
#

so as a result, there's no discrepancy at x=-1

#

since limit exists there

#

and is finite

clear glade
#

Right

#

Thank you

undone pawn
#

np

signal mountain
#

how do i solve (lnx)^2 + 3lnx = 1 ? not sure how i deal with the (lnx)^2 term :/

serene heath
#

Set t=lnx and go from there

signal mountain
#

thanks!

sick lava
#

how am i supposed to get the angle between i + j and i + j -k

stuck lark
#

dot product definition is one way

sick lava
#

what do i do with the extra K

stuck lark
#

these guys are in 3d space. think of the first guy as having 0k component

sick lava
#

kk

#

dot product 2 right?

#

2 / (srq2 * srq1)

#

oh

sick lava
#

Its not working

#

im getting

#

2 / srq 6

#

arcsine of that is .86

#

which is wrong

stuck lark
#

@sick lava idk how you got 0.86 but dot product uses cos, and make sure your calculator’s in deg mode

sick lava
#

oh i got

#

it

#

thank

#

s

stuck lark
#

Naisu

sick lava
#

how do i convert (-srq3 + i)^6 into exponential form

stuck lark
#

Know how to convert -sqrt(3)+i to exp form?

sick lava
#

to the 6th

#

i need to change ti to standard form

#

a + bi

vale basin
#

Can sombody help me with this lim

#

I cant solve it

stuck lark
#

^6 is easier to do in exp form so I advise you convert the inner to exp form

sick lava
#

how

uncut mulch
#

find r and theta

sick lava
#

how do u find theta

#

tan inv?

stuck lark
#

yes arctan

pseudo sonnet
#

can someone help me with vector c) problem

trail smelt
#
Vectors are parallel if they have the same direction. Both components of one vector must be in the same ratio to the corresponding components of the parallel vector.
pseudo sonnet
#

thanks got my final in 20 mins

trail smelt
#

good luck

viscid thistle
#

What does evaluate means here?

fluid shore
#

Calculate

#

Find the value of the sum

#

They have a number associated with each sum that you can get. So, get that number.

viscid thistle
#

Oooh okay

odd dagger
#

nice sigma

fluid shore
#

Yes the first 35 terms

#

Oof nice handwriting 🙂

viscid thistle
#

Thanks guys! :'D

#

What am I supposed to do with this?

#

Ooh I think I know~~ but please help :'l

fluid shore
#

Eh there’s a formula for finding the sum using the first and last term of the series

viscid thistle
#

I know!

fluid shore
#

I suggest you derive it first lmao

viscid thistle
#

;_; how do I do that?

fluid shore
#

Write out a general arithmetic series with initial term a1 and common difference d

viscid thistle
#

Is not the right diference

#

52 would be the right diference

#

But it doesn't make sense because A_14 ≠ 146

#

A_3 = 146

#

sadcat Hello?

#

Ooooh wait

#

I made an oopsie

odd dagger
viscid thistle
sick lava
#

In the problem cos theta = 1/4, csc theta > 0

#

what does the csc theta > 0 mean

odd dagger
#

@viscid thistle when you divided by 13 why didnt you minus 42 first

#

you didnt divide 13 to the 42

viscid thistle
#

I didn't know if I had to do the right PEMDAS or the inversed PEMDAS :'(

odd dagger
#

146 = 42 + 13d
104 = 13d
d = 8

#

@sick lava it means csc(x) > 0

sick lava
#

so cos > 0?

odd dagger
#

whats the actual problem

#

no

#

1/sin > 0

sick lava
#

oh yes

#

1/sin is restricted to

#

pi / 2 = -pi /2?

#

so restricted to pi / 2 to pi?

odd dagger
#

no

viscid thistle
#

So every time I want to solve the left side of a function I need to use inversed PEMDAS

odd dagger
#

that is inverse sine

sick lava
#

oop

odd dagger
#

@viscid thistle or

sick lava
#

whats the difference between 1 / sin and sin

odd dagger
#

when you divide by 13 do it to every term

#

so it remains a true statement

viscid thistle
#

Uhmm okay okay

odd dagger
#

if a=b then a/13 = b/13

#

the error you made was like

#

a = b + 13c

#

a/13 = b + c

#

this is not the same

#

you would do a/13 = b/13 + c

viscid thistle
#

I didn't knew because, I thought you only cancel 13 to 13 and not the whole thing because 13 is just affecting the d

odd dagger
#

nah when you manipulate equations you wanna take operators to the entirety of both sides

#

not just choosing some terms of both sides and assuming that's equivalent

#

7 = 7
7 = 3+4
7/4 = 3 + 4/4 (error: not dividing the 3 by 4 too)
7/4 = 3 + 1
7/4 = 4
7 = 16

#

@viscid thistle see how the error of not dividing the entirety of both sides of the equation by 4 doesn't keep it equivalent?

#

7 = 7
7 = 3 + 4
(7)/4 = (3+4)/4
7/4 = 3/4 + 4/4
7/4 = 3/4 + 1
1.75 = 0.75 + 1
1.75 = 1.75

#

Here we divide the entirety of both sides by 4 and it remains equivalent

sick lava
#

um

#

how do i find sin theta / 2

odd dagger
#

@sick lava can you post the question

sick lava
#

when cos theta = 1/4

#

yes

odd dagger
#

ah ok

sick lava
#

, csc > 0

#

im using the identity

odd dagger
#

so you want $\frac{\sin{x}}{2}$

#

?

obsidian monolithBOT
sick lava
#

um

#

no its sin (theta / 2)

#

sorry

odd dagger
#

oh ok

viscid thistle
#

Yeah...

odd dagger
#

set up system of equations for n and d with a_n and s_n formula @viscid thistle

viscid thistle
#

thonkg oh wao

sick lava
#

oh

#

I got sqr3/8

odd dagger
#

@sick lava so do you know $\sin{\frac{x}{2}} = \pm \sqrt{\frac{1-\cos{x}}{2}}$

obsidian monolithBOT
sick lava
#

yes

#

i plugged in

#

srq (( 1 - 1/4) / 2)

odd dagger
#

right

sick lava
#

+- srq (3/8)

#

it would be the positive one?

odd dagger
#

whats your reason for that

sick lava
#

csc > 0?

odd dagger
#

and?

#

so 1/sin(x) > 0

sick lava
#

uhh

#

idk

odd dagger
#

if 1/f(x) is positive, f(x) is positive too right?

sick lava
#

yea?

odd dagger
#

@sick lava post the question

sick lava
#

cos theta = 1/4, csc theta > 0, find sin (theta/2)

#

no idea

odd dagger
#

well i mean

#

sin(x/2) = \pm sqrt(3/8)

#

sin(x) > 0

#

2sin(x/2)cos(x/2) > 0

#

but cos(x/2) will be \pm too

#

so both \pm sin(x/2) work for some interval in sin(x)>0

sick lava
#

so it would be +-

viscid thistle
#

And I don't know how to continue

fluid shore
#

Eh what’s the question?

dim jungle
#

^

viscid thistle
#

Okay, ^^ that complicated

#

I want the difference

trail smelt
#

@viscid thistle do you know the right answer?

viscid thistle
#

Yeah, there should be 12 n terms adding up to 690

trail smelt
#

arithmetic series aren't sharp on my memory anymore but i picked the following formula online $Sn = n*(\frac{a1+an}{2})$

obsidian monolithBOT
trail smelt
#

yup

#

that's what i got

viscid thistle
#

What n then?

trail smelt
#

i got n = 12

viscid thistle
#

And how do I get it by myself

trail smelt
#

you pick that formula

#

substitute Sn, a1 and an with the values you have

#

then you solve for n

viscid thistle
#

But am not familiarize with it :'( I can't change that type of thing when I have a midterm on Monday :(

trail smelt
#

what do you mean?

#

you got me confused xD

viscid thistle
#

The formula I do for Sn is the following

trail smelt
#

show me

viscid thistle
trail smelt
#

are you sure that's the only formula you have relating to this topic?

viscid thistle
#

Yeah!

#

I haven't learned other formulas to get Sn :(

trail smelt
#

i havent touched on this in a loooong time but i am almost certain that we had a formula like this to determine Sn

#

let me think

viscid thistle
#

I could use it, but my teacher requires me to understand they reason for every variables to be in it, and I can only explain the one I showed you

trail smelt
#

I can send you a video explaining the deduction of that formula

viscid thistle
#

You can send it, but I'm not promising anything. Is a midterm...

viscid thistle
trail smelt
#

I don't see why that formula wouldn't be used in that situation since that it is so straight forward

#

I'll have a look

viscid thistle
#

I could use it, but I don't feel confident enough to use it in my midterm

trail smelt
#

Yup, better play it safe

viscid thistle
#

:) am glad you understand

#

So that n I got seems too much

#

Yeah, never in a million years

trail smelt
#

what do you mean?

odd dagger
#

S_n = n/2 (2a + (n-1)d)

#

pr sure you use that

#

@viscid thistle whaf u asking

viscid thistle
#

Don't worry guys

#

I got a big brain epiphany

odd dagger
viscid thistle
sturdy haven
#

Are absolute extrema also relative extrema?

odd dagger
#

yes

#

relative extrema can just mean an extrema

sick lava
#

tan x = -8/9; x in quadrant II; find cos x

#

Im getting 9 / srq145

#

supposedly thats wrong

wise kelp
#

If it's in quadrant II then the cosine should be negative

#

@sick lava

viscid thistle
#

Anyone here that can help me with a simplification question

proud raven
#

post it

viscid thistle
#

M

#

K

native sequoia
#

,rotate

obsidian monolithBOT
viscid thistle
#

Anyone

#

Nevermind

vestal marlin
#

Is this undefined from x=-4/3 to -2?

viscid thistle
#

I'm guessing every multiple of 4 months the number of rabbits multiples by 3

#

What you guys think

lethal oracle
#

Yes

viscid thistle
#

so this one is a bit confusing

#

So it says laber force = L(x)

#

right

#

then population is P(x)

#

nvm

#

its A

#

idk why i even asked

eternal flume
#

Hello

#

Is there a way I can solve this without using logaritms?
3^(3x-1)=1

willow bear
#

well you can recognize that 1 = 3^0

eternal flume
#

ah, thanks

#

I completely forgot about that 😂

eternal flume
#

And how can I solve this?
9^(v+2)+5*9^(v+1)=14

willow bear
#

isolate 9^v first and hope the rhs is a nice power of 3 i guess

eternal flume
#

Okay, this is what I've done:

9^v = y
y^2+5y-14=0
D=25+4*14=81
D^(1/2) = 9
y1 = (-5+9)/2 = 2
9^v = 2```
How should I continue?
undone pawn
#

how did you get the quadratic??

willow bear
#

uhhh

#

$9^{v+2} \neq (9^v)^2$

obsidian monolithBOT
undone pawn
#

$9^{v+2} = 9^v \cdot 9^2$

obsidian monolithBOT
eternal flume
#

I see, thanks

nova dew
#

$\lim_{x\to\infty} \frac{5^x}{e^x} = \infty$ right

obsidian monolithBOT
nova dew
#

and for e^x / 5^x it would be = 0

#

right

serene heath
#

Yus

void quiver
#

i also need the work for it please

viscid thistle
#

B is not so much computation as it is thinking about what the problem means

void quiver
#

i just need help

viscid thistle
#

it wants to know what values of x (amounts you can cut off) are practical for this situation

#

for example

#

can you cut off 100 inches from the box?

void quiver
#

well im mostly stuck on

#

b

viscid thistle
#

my last 3 lines are food for thought for B

void quiver
#

oh

#

then no

viscid thistle
#

so when does the amount cut off become impractical

void quiver
#

5

#

?

viscid thistle
#

yep

void quiver
#

so then D: (0,5)?

viscid thistle
#

yep

void quiver
#

ah ok

#

so then i got this now