#precalculus

1 messages · Page 269 of 1

opaque idol
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Oh

obsidian monolithBOT
burnt sonnet
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so it has the correct graph value but!

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is it a max point?

opaque idol
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No

burnt sonnet
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ah then we need to modify

opaque idol
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Ok how we do that?

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We multiply the -3?

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Or plug in?

burnt sonnet
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well so what should the sign be infront of the x^2 ?

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negative or positive?

steel swan
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how hard is skipping pre calc

opaque idol
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Positive

burnt sonnet
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try and plot x^2 does it have a max point?

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and then try and plot -x^2

opaque idol
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No

burnt sonnet
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okay

opaque idol
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No

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I mean maybe

burnt sonnet
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,w plot -x^2

obsidian monolithBOT
burnt sonnet
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This one has a max point at (0,0)

opaque idol
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Yes

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So the a with ge negative

burnt sonnet
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okay so we want the sign on the x^2 term to be negative

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yes

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f(x)=-x^2+bx+c we have now 🙂

opaque idol
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Ok cool

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Then do we plug in the number of 3 and 6?

burnt sonnet
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lets see if we can find a b and c so that it f(-3) is equal to -6

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f(-3)=-6 this is what we want

opaque idol
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Ok

burnt sonnet
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$f(-3)=-(-3)^2+b(-3)+c=-6$

opaque idol
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Mhm

obsidian monolithBOT
burnt sonnet
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oh we need it to be the max point aswell

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hmm have you shifted functions before

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like if you look at f(x) and then at f(x-1)

steel swan
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can someone explain binomial theorm

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im still confused

opaque idol
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No?

burnt sonnet
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We are working here wait for your turn 😛

opaque idol
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I don’t think so

burnt sonnet
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okay

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look at this

steel swan
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k.

burnt sonnet
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f(x)=-x^2 , then f(x-1)=(x-1)^2

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,w plot -x^2 and -(x-1)^2

obsidian monolithBOT
opaque idol
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The graph shifted

burnt sonnet
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yes it shifted so now the max is at x=1 right?

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this is what f(x-1) did

opaque idol
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Yes

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So the b will be negative?

burnt sonnet
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we will see

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take f(x)=-x^2-6

opaque idol
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Mhm

burnt sonnet
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,w plot -x^2-6

obsidian monolithBOT
steel swan
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sooooooo

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hi

opaque idol
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?

burnt sonnet
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at what point does it have it's max point?

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what is the x and y coordinate

opaque idol
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The Max is (0,-6)

burnt sonnet
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Yes

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and where did we want it to be?

opaque idol
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(-3,-6)

burnt sonnet
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do you remember how we did to shift the all the points of the function? 😄

opaque idol
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Yes

burnt sonnet
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f(x)=-x^2-6

opaque idol
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For this we have to move to the left 3 times a

burnt sonnet
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this has a max at (0,-6)

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and yes we want to move allt points three steps to the left

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so when we took f(x-1) we shifted to the right

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so if we take f(x+1) we shift to the left

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,w plot -(x+1)^2-6

opaque idol
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Yeah

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We can leave the y the way ad it is

burnt sonnet
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,w plot -(x+1)^2-6

obsidian monolithBOT
burnt sonnet
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So this was f(x+1) what should we put in?

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x+ what?

opaque idol
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Um

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3?

burnt sonnet
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yes

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,w plot -(x+3)^2-6

opaque idol
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Ok cool

obsidian monolithBOT
burnt sonnet
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and then if you write on in standard for you have to simply it

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-(x+3)^2-6, write this out on ax^2+bx+c form

opaque idol
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So

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-x^2-3x-6?

burnt sonnet
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there is a square

opaque idol
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Yes I put that

burnt sonnet
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$-(x+3)^2-6=-(x^2+6x+9)-6$

obsidian monolithBOT
opaque idol
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So would you have to do 9-6?

burnt sonnet
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$-x^2-6x-9-6=-x^2-6x-15$

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I belive

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,w plot -x^2-6x-15

obsidian monolithBOT
opaque idol
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So the answer will be -x^2-6x-15?

burnt sonnet
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that is one answer

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there is infite solution 🙂

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This is how I would view it there might be smarter ways to go about it!

opaque idol
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So I should put -x^2-6x-15?

burnt sonnet
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I mean do you think it fits the description?

opaque idol
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I think so

burnt sonnet
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it it a quadratic function with max value at (-3,-6)

opaque idol
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Imma put it in the calc.

burnt sonnet
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Good do that to be sure

opaque idol
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How do I find the max?

burnt sonnet
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Have you done derivatives?

opaque idol
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Ooo

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O

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No

burnt sonnet
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oki

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I guess if you have a graph plotter

opaque idol
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Yeah

burnt sonnet
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you can just plot it between some x-values around x=-3 and see if it is a max

steel swan
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@burnt sonnet hey quick question

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should I skip precalc

burnt sonnet
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hey I am helping someone else

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Probably not

steel swan
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uhm can you explain one sentence

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why not

burnt sonnet
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If you are asking you probably need it

steel swan
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no

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im just asking whether I should skip it

opaque idol
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Ohh ok

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Let me try

steel swan
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khan academy explains it well

burnt sonnet
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yeah and I said if you ask that question then you should probably do it

steel swan
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I'll ping u later nvm

burnt sonnet
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haha don't

steel swan
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im interputing

burnt sonnet
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And yes you kinda were, you need to wait on your turn, and I dunno if you should skip it...

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@opaque idol are u able to work it out?

steel swan
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@burnt sonnet so u

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since jpiggy is not here for now

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May I ask why I shouldnt skip pre calc

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I mean I did most of the khan academy course

burnt sonnet
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If you felt safe about it you wouldn't ask

steel swan
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and it seemed pretty easy

burnt sonnet
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I don't even know what this is we don't do that in my country 😛

steel swan
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bruh

burnt sonnet
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But generally if people ask about it

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they should do it

steel swan
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wait where do u live

burnt sonnet
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europe 😄

steel swan
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ohhhhh

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ahahah

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I got it

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nice

burnt sonnet
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Maybe try and take some online test for it and see if you know it well enough

steel swan
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yes

burnt sonnet
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kahn academy isn't the most rigorus

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But they give the concepts ok I guess 🙂

steel swan
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yea

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I need to read the textbook lool

burnt sonnet
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Ye that is good for further studies

paper pier
willow bear
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is that $y = x\csc(x^2)$ or $y = x(\csc(x))^2$?

obsidian monolithBOT
sick steppe
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Im assuming csc(x^2)

drowsy helm
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could someone help me solve this pls

willow bear
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half these n's are horribly written

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$\lim_{n \to \infty} \sqrt[n]{n}$ is this what you want the limit of?

obsidian monolithBOT
drowsy helm
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yeah that's it

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I write in cursive

willow bear
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write $n^{1/n}$ as $e^{\frac{1}{n} \ln(n)}$

obsidian monolithBOT
drowsy helm
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alright and then what

willow bear
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$\frac{\ln(n)}{n} \to 0$

obsidian monolithBOT
drowsy helm
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oh alright so it converges to 0

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ty

willow bear
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e^0 isn't 0

drowsy helm
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yeah it's 1

quaint mason
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Is anyone good with piecewise function, i somehow got this problem right 2 weeks ago and somehow forgot how to solve it :)...

viscid thistle
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Just post it

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!r1

quaint mason
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I just need a review on part a

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Lol..

quaint mason
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Nvm i got it

pallid marlin
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1-sin^2\left(\frac{7\pi }{6}\right)

viscid thistle
blissful ridge
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Try to write i in the form of e^{ix}

fickle plaza
willow bear
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Q1a?

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@fickle plaza

fickle plaza
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Yeah @willow bear

willow bear
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ok

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what have you done so far?

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have you obtained the y-coordinates for A and B?

fickle plaza
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thing is I don't really know how to do that, I can use differentiation of first principles to differentiate but that's about it I don't know about X or y cords ;-;

willow bear
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...

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ok so like this is way too early for differentiation

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are you... telling me you don't know anything about the coordinate plane??

fickle plaza
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dnusbaj nononono, I just don't understand how to use differentiation to find the y cords

willow bear
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no??? you're not using differentiation yet?? anywhere?

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you're overthinking it

fickle plaza
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I'm not?....

willow bear
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A lies on the curve y = x^2 - 6x + 5 and its x-coordinate is 2. what is its y-coordinate?

fickle plaza
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idk ;-;

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oh lmao

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Nvm

willow bear
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so what is it then

fickle plaza
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-3

willow bear
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there we go

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B also lies on the curve y = x^2 - 6x + 5 but this time its x-coordinate is (2+h).

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what is B's y-coordinate?

fickle plaza
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(4+2h+h^2) - 6(2+h) + 5

willow bear
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no, check again

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(2+h)^2 ≠ 4 + 2h + h^2

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also, simplify.

fickle plaza
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h^2 - 2h - 3

willow bear
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ok great

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so A and B have coordinates (2, -3) and (2+h, h^2-2h-3) respectively.

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are you able to find the gradient of AB?

fickle plaza
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mhm

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I think

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Y - y1 / X - x1

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but how do I do this when I've got h terms?

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-3 - H^2-2h-3 / 2 - 2+h

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ifkhnjfdlksjhfkj

willow bear
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okay so there are several things wrong with this

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most starkly the absence of parentheses and the random capitalization

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why not write $\frac{(h^2 - 2h - 3) - (-3)}{(2+h) - 2}$

obsidian monolithBOT
fickle plaza
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yep

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then how do I continue?

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it can't be simplified right?

willow bear
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yes it can

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it can be simplified plenty

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and in fact SHOULD be.

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@fickle plaza sorry for the delay, had some irl shit to attend to

fickle plaza
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O cool np

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I simplified to h-2

north pagoda
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Anyone know how to solve this $ \frac{3^{3-x} } { (3^{3-x} ) + 3^x } = .5 $

obsidian monolithBOT
viscid thistle
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What have you tried so far

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& where are you stuck at

north pagoda
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I think I reduced it to $ \frac {3^3 } {3^3 + 3^{2x}} = .5$

obsidian monolithBOT
north pagoda
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but not sure what to do here

viscid thistle
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Aight well

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From here we can do

obsidian monolithBOT
viscid thistle
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$27=\frac12 (27+3^{2x})$

obsidian monolithBOT
viscid thistle
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Expand the RHS

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@north pagoda

north pagoda
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nice

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$ 54 = 27 + 3^{2x } $

obsidian monolithBOT
viscid thistle
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Yeah

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That's another way

north pagoda
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$ 27 = 3^{2x} $

obsidian monolithBOT
viscid thistle
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Yeah

north pagoda
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now is where I confuse

viscid thistle
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From here you can do it by logic/trial or just log properties

north pagoda
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how would you use log properties

viscid thistle
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log both sides

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$\log(27)=\log(3^{2x})$

obsidian monolithBOT
north pagoda
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yo this actually makes sense how logs work now

viscid thistle
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Glad to hear

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Now you know how to continue from here?

north pagoda
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yes good stuff

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thank you !

viscid thistle
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Great

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Yw!

opaque idol
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Can someone help?

viscid thistle
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Rule 1. Don't ask to ask, just post it

opaque idol
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Find the vertex, the axis of symmetry and range

viscid thistle
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@opaque idol what have you tried

opaque idol
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I got the vertex (-8,-32)

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Axis=-8

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Range=

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Y>=-32

viscid thistle
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-8 isn't an axis

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x=-8 is an axis

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,w plot x=-8

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See?

obsidian monolithBOT
viscid thistle
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But yeah everything else is correct

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@opaque idol

opaque idol
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Oh ok

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Thank you so much!

opaque idol
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Can anyone?

viscid thistle
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Have you got anything?

opaque idol
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No not really

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It’s hard

viscid thistle
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Okay don't worry

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Do you know what f(x+4) means

opaque idol
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Yeah

viscid thistle
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Or how to get f(x+4)

opaque idol
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Maybe

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X^2-2x+3+4

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@viscid thistle

viscid thistle
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Not sure how you got there

opaque idol
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Oh lol

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Then idk

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It’s kinda hard lol

viscid thistle
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Say we have h(x)=x-3
Then h(👀 )=(👀 )-3
h(🍞 )=(🍞 )-3
h(71863849916)=(71863849916)-3
h(x²+x)=(x²+x)-3

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Does this clarify it

opaque idol
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Wym

viscid thistle
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It's an analogy i use to make you understand that whatever is inside the parens on h(x) is gonna be plugged into the x

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As i did with the bread, the eyes, the number and the x²+x

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Do you understand what i did

opaque idol
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Oh ok I get it now

viscid thistle
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It's simpler than you think

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Ok great

opaque idol
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Yeah I had to say it out loud

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Thank you

viscid thistle
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Oh can you get f(x+4) by yourself then?

opaque idol
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Yeah

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Is the right answer (0,2)

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?

viscid thistle
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Great. Be sure that when plugging, you use parenthesis

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Uh wait

opaque idol
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Yeah?

viscid thistle
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i'm not getting that exactly

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What did you got for g(x) first

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Like the expression of g

opaque idol
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I think (1,3)

viscid thistle
#

No like the function g

opaque idol
#

Oh

viscid thistle
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You got g(x)=......

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What did you got for that

opaque idol
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Would u plus in x^2-2x+3+4?

viscid thistle
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If you have f(x)=x²-2x+3
Find f(x+4)

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Let's do this step by step

opaque idol
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Wait so

viscid thistle
#

Say we have h(x)=x-3
Then h(👀 )=(👀 )-3
h(🍞 )=(🍞 )-3
h(71863849916)=(71863849916)-3
h(x²+x)=(x²+x)-3
Remember this

opaque idol
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Would U do (x+4)-3?

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Would it make it x+1?

viscid thistle
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I'm confused on what you are doing

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From where -3

opaque idol
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I got it from the g(x)

viscid thistle
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Did you do g(x)=f(x+4)-3=(x+4)-3=x+1

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?

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Because that's not what we want to do

opaque idol
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Ohh

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Ok i see

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Sorry then

viscid thistle
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Don't be sorry

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So

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If you have f(x)=x²-2x+3
Find f(x+4)

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Let's do this step by step

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Forget about g for now

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And focus on that ^

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What you want to do is to plug x+4 into all the x you see at x²-2x+3

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What do you get

opaque idol
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(X+4)^2-2(x+4)+4

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3*

viscid thistle
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Yes!

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Good job

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So now

opaque idol
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Ok

viscid thistle
#

Let's try to simplify that

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Simplify $(x+4)²-2(x+4)+4$

obsidian monolithBOT
viscid thistle
#

Now we get into the obscure world of algebra

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Remember that (a+b)²=a²+2ab+b² and NOT a²+b²

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Try to simplify that

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@opaque idol

opaque idol
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(X+4)^2-2x-8+4

viscid thistle
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Yes

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So far so good

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Expand (x+4)² now

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@opaque idol ???

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Do i have to ping you?

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For you to answer?

opaque idol
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Yeah sorry lol

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That would make it (x+4)(x-4)

strong fossil
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Guys anyone here know leibniz formula ?

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I kinda have a question concerning it

viscid thistle
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That would make it (x+4)(x-4)
@opaque idol how?

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(x+4)² is (x+4)(x+4) on any case

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But why not just use $(a+b)²=a²+2ab+b²$ instead of expanding (a+b)(a+b)

obsidian monolithBOT
opaque idol
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Ohhhh

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Ok I see

viscid thistle
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What would you get

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Remember that we are at

(x+4)^2-2x-8+4

limpid wyvern
viscid thistle
#

Alright i'm tired of waiting and getting ghosted. I'm out unless you change your attitude.

limpid wyvern
#

me?

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@viscid thistle

viscid thistle
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No. Jpiggy

limpid wyvern
#

o

blissful flower
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Could any of you help me get the flow of how this works, I've studied it before but it's been years so I've forgotten

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As in the steps you take to solve it

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I'd love to google myself but I'm not quite sure what to google about it

velvet granite
#

so you've got a composite function

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Meaning, first, you need to find the inverse of f(x)

uncut mulch
#

why not just apply the definition of the inverse

velvet granite
blissful flower
#

Thank you, I didnt see someone answered

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Thanks a lot

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i got −5^√5 for the inverse of x^5-3

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correct?

uncut mulch
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no

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also

why not just apply the definition of the inverse

velvet granite
#

Whats that?

uncut mulch
#

$f(f^{-1}(x)) = x$

obsidian monolithBOT
velvet granite
#

But you still have to do the inverse and do a composite function right

uncut mulch
#

nope

velvet granite
#

Fr

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Wish they taught me that in school

uncut mulch
#

but you should deduce that an inverse actually exists for that function

blissful flower
#

i wish i was taught that too lol

steady seal
#

how do i approach this

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lol wait wrong channel lol

past meadow
#

split it up and write tan^2x as 1+sec^2x and it will simplify down but yeah wrong channel

sick steppe
#

@steady seal do you still need help?

fossil locust
#

how do i approach this
@steady seal 5-5sin^2theta = 5 (1 - sin^2 theta)

sick steppe
#

@fossil locust try not to just give the answer if you can 🙂

fossil locust
#

ohh ok

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gave them a starting approach

lament fiber
#

<@&286206848099549185>

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please help

viscid thistle
#

Guys how to solve it ?

humble current
#

@lament fiber you will get DNE

lament fiber
#

yeah I was about to correct that sorry

humble current
#

Cause tan(0) = 0/1

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wait actually

lament fiber
#

it's been a while since I've done this I'm basically starting over

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lim sin x/x =1

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lim tan x/x=1

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I think it'll work

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yes it should

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as x approaches 0 lim sin(x)/x=1

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small angle approx is the same thing

humble current
#

@lament fiber I just did it on paper, it's actually indeterminent

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because tan(0) = 0 and sin(0) = 0

lament fiber
#

yeah you're right

serene heath
#

divide top n bottom by x @viscid thistle

lament fiber
#

you'll get 0/0 then

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I suggested the same thing

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(1-1)/(1-1)

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@serene heath

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and they aren't supposed to use l'hopital

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also can someone help me in #help-0
I asked here but it got ignored like my prev question so I removed it from here and stuck it in questions and even pinged the Helpers twice sadcat

viscid thistle
#

@lament fiber are you still stuck on that limit?

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divide top n bottom by x @viscid thistle
@serene heath
U'll get 0/0

lament fiber
#

it was @viscid thistle ‘s question @viscid thistle

viscid thistle
#

Oh

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@viscid thistle are you still stuck on that limit

whole vessel
#

\frac{x^{2}}{4}-\frac{\left(y-3\right)^{2}}{5}=1

You can input this into desmos if you want. Why is there a hole at y = 3 for the vertices?

sonic arrow
#

for all $ A,B \in \mathbb{R}^{+}$ such that $A \neq B$, and that neither $A$ or $B$ are $1$, and $\log_{A}B = \log_{B}A$. Find $AB$

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the problem is that if you let $n = \log_{A}B = \log_{B}A$ then $A^n = B$ and $B^n = A$. Therefore $AB = (AB)^n$ and here $n$ can only be 1. But that means that $A = B$

#

any ideas?

obsidian monolithBOT
sonic arrow
#

oh nvm im stupid

warped dagger
patent beacon
#

You're taking the square root of both sides which should give sqrt(9π) not sqrt(9)π

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@warped dagger

warped dagger
#

Okay, what do you mean by that?

lapis sphinx
#

Step 3

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18 pi/2pi is 9 not 9pi

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@warped dagger

warped dagger
#

alright, may i know why? it just kind of doesnt make sense to me

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because pis cancel out?

lapis sphinx
#

Exactly

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Pi is still a number

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Imagine it was x

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If u have 18x/2x it would be 9 not 9x

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Similarly 18 pi/2pi is 9 not 9pi

warped dagger
#

i see, thanks.

lapis sphinx
#

Np

warped dagger
#

was there anything else that i did wrong there?

lapis sphinx
#

I don’t believe so

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Yeah other than r=3 I think ur fine

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However

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If in some scenario u did in fact end up with r^2=9pi, r would equal 3*sqrt(pi) not 3pi

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@warped dagger ^ sry for tag, responded late

knotty echo
#

anyone?

livid fjord
#

What did u get for a?

knotty echo
#

-3/8

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a was straight forward but i cant seem to manipulate to B

livid fjord
#

Yeh bro I can’t help u cause I’m dumb but I think since it’s been 15 minutes you can @ the helpers

knotty echo
#

<@&286206848099549185> I need help with the trig question

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someone i just can't get sin - cos by itself

knotty echo
lapis sphinx
#

uhh

#

Hm

#

Chene gimme 1 minute

#

Think I can do it

knotty echo
#

thanks

#

this worksheet is unreasonably hard

#

@lapis sphinx any progress?

lapis sphinx
#

Yes almost done

knotty echo
#

I can't get a hair out of this problem

lapis sphinx
#

Change tan and cot into terms of sin and cos and then common denominator

#

Try from there

knotty echo
#

I got $\frac{sin^2x+cos^2x}{sinxcosx}=8$

obsidian monolithBOT
lapis sphinx
#

Yep and what does the numerator equal

knotty echo
#

1

lapis sphinx
#

Nice

#

So then isolate sinxcosx

#

Lmk what u got

knotty echo
#

well i got $sinx=\frac{8}{cosx}$ and $cosx=\frac{8}{sinx}$

obsidian monolithBOT
knotty echo
#

well adding them directly wont do me any good

lapis sphinx
#

Keep the sin and the cos together

knotty echo
#

how so?

lapis sphinx
#

Sinxcosx=1/8

knotty echo
#

then what do i do?

#

thats where I'm left with nothing else to do

lapis sphinx
#

This one requires a bit of creative thinking . Can u think of anyway possible to get a value sinxcosx

#

Utilizing not only ur first equation, but ur second one too

knotty echo
#

not sure

lapis sphinx
#

I’ll give u a hint, it has to do with squaring the second expression

knotty echo
#

lemme try

#

well tanx + cotx = $tan^2x + 2 + cot^2x$

obsidian monolithBOT
lapis sphinx
#

I think u missed a part of the term in the middle but that’s alright, I was referring to the sinx+cosx

#

How could u get sinxcosx from that

knotty echo
#

something to do with $1+tan^2x=sec^2x$ and $1+cot^2x=csc^2x$?

#

this latex rendering speed is slow 😦

lapis sphinx
#

Hm

obsidian monolithBOT
knotty echo
#

im guessing something to do with these?

lapis sphinx
#

Not really. Think back to the sin x + cosx part

#

Strictly from that expression

#

What operation would u perform on that expression to give u sinxcosx

knotty echo
#

oh you can convert tanx and cotx into its sines and cosines

lapis sphinx
#

Nahnah just try this: What operation would u perform on that expression to give u sinxcosx

#

Multiply, add, subtract, exponent, log? What would give u sinxcosx

knotty echo
#

multiply?

lapis sphinx
#

By what?

#

Here’s a hint

#

Think about exponent

knotty echo
#

$cos^2xsin^2x$ to cancel out the denominators of tan and cot

obsidian monolithBOT
knotty echo
#

right?

lapis sphinx
#

Hm

#

How would u use an exponent to get there tho

#

What is the simplest exponent that we know?

knotty echo
#

square

lapis sphinx
#

The one that we learned first, other than 1

#

Exactly

#

Try squaring it

#

See what u get

#

By it, I mean squaring sinx+cosx btw

knotty echo
#

oh ok

#

sin^2x + cos^2x + 2cosxsinx

north niche
#

Wat is the inverse of f(x) 5x-2

lapis sphinx
#

Bingo

#

How can u simplify it further

knotty echo
#

substituting cosxsinx with 1/8?

north niche
#

Wat is the inverse of f(x) 5x-2

lapis sphinx
#

Sure, and how about the first two terms?

knotty echo
#

which is 1

lapis sphinx
#

Yep so what do we get

knotty echo
#

1 + 1/8

lapis sphinx
#

Remember it’s 2(sinxcosx)

knotty echo
#

oh

#

1.25

north niche
lapis sphinx
#

Leave it in fraction form, what’s the left side of the equation?

knotty echo
#

not sure

lapis sphinx
#

How did u end up with sin^x + cos^x + 2sinxcosx

knotty echo
#

(cosx + sinx)^2

lapis sphinx
#

Exactly

knotty echo
#

then take square root?

lapis sphinx
#

U got it

knotty echo
#

yay thanks

livid fjord
#

Yooo noice

lapis sphinx
#

What would be the final answer?

#

And np

north niche
#

Wat is the inverse of f(x) 5x-2

knotty echo
#

$sinx + cosx = \frac{\sqrt{5}}{5}$

obsidian monolithBOT
livid fjord
#

Bro derp u gotta wait for chene to finish being helped and then can I get help cause I’ve been waiting for and hour

knotty echo
#

4

#

for denominator

#

so root 5 / 2

lapis sphinx
#

So (sinx+cosx)^2 = 5/4

#

Yes exactly

#

But what happens

#

When u take sqrt

#

Think abt the signs

knotty echo
#

$\pm 2$

obsidian monolithBOT
lapis sphinx
#

Yup

#

So what’s the final answer

knotty echo
#

$\frac{ \sqrt{5} }{ \pm 2 }$

obsidian monolithBOT
lapis sphinx
#

Pm on the outside but yeah

#

Nice job man

knotty echo
#

thanks

lapis sphinx
#

Np

livid fjord
#

Bro I keep making absurdly wrong one’s. This may be too large of a problem but I would really appreciate some help

#

I need to make 2 rational functions that meet those requirements

knotty echo
#

i dont know anything about rational functions 😦

#

sorry

livid fjord
#

Bro all good

#

I’m glad that u got help tho u had to wait a while

lapis sphinx
#

Scout I can give u a 2 minute explanation for the first one then I gotta go man

livid fjord
#

Yeh anything helps

lapis sphinx
#

Aight so what’s a removable

#

Or when can u get one

livid fjord
#

Well it’s a hole

lapis sphinx
#

Yup, but how does it occur

livid fjord
#

U get it when you can factor out of the numerator and denominator

lapis sphinx
#

Exactly

livid fjord
#

Like if u have (x+4) in the numerator and denominator

lapis sphinx
#

Yeah

#

So the problem is asking for u to have 2 renovables

#

So how would u do so

livid fjord
#

x(x+4)(x-8) over (x+4)(x-8)

lapis sphinx
#

Nice, and then it asks for 3 infinite

#

How do u get that

livid fjord
#

That’s the part I’m having trouble adding

#

To the discontinuities

lapis sphinx
#

So inf discontinuity is a vertical asymptote

#

U knew that?

livid fjord
#

Ok yeh

lapis sphinx
#

I mean, for our level

#

So

livid fjord
#

Yee

lapis sphinx
#

How do u get a vert asymptote

livid fjord
#

Domain

#

So it would be -4 and 8?

lapis sphinx
#

Yup, but specifically changes made to the function

#

Well

#

Remember that those are the holes

#

So they can’t be the inf discontinuities

#

U would have to make up 3 more

livid fjord
#

Um

lapis sphinx
#

So

#

If I had function 4/(x-7) where is vert asymptote

livid fjord
#

7?

lapis sphinx
#

Exactly

#

How’d u come to that

livid fjord
#

I figured out what x could equal that would make the denominator equal to zero

lapis sphinx
#

Bingooo man

#

So what would u do to the original equation with the holes in it already

livid fjord
#

Idk

#

That’s the part I have trouble with

lapis sphinx
#

Lemme write

#

k

#

@livid fjord

livid fjord
#

K imma write it real quick

lapis sphinx
#

just write the final expression i wrote

#

so how could we finish it up

#

based off what i did

livid fjord
#

Well the numerator would be x^3-4x^2-32x

lapis sphinx
#

yes

#

but dont worry about simplifying the bottom yet

livid fjord
#

Ok

lapis sphinx
#

just

#

how would u add on to what i added with the x-7

livid fjord
#

To the numerator

lapis sphinx
#

nahh cuz we tryna do vert asymptotes which always go in denominator

livid fjord
#

K

lapis sphinx
#

so what would u do

livid fjord
#

No clue

lapis sphinx
#

how do u get a vert asymptote again? refer to what i did with 4/(x-7)

livid fjord
#

Oh

#

So it would be -4,8, and 7?

lapis sphinx
#

nope, cuz -4 and 8 are already holes so we cant use them for infinite discontinuites/vert asymptotes

#

we gotta create new ones

livid fjord
#

Division?

lapis sphinx
#

and u need 2 more new ones

#

i mean, we just put x-7 in the denominator to get an asymptote

#

so what would we do to get 2 more

livid fjord
#

Hm

lapis sphinx
#

Cuz the -4 and 8 are already used up

#

So we gotta make 2 more

livid fjord
#

Make more idk

lapis sphinx
#

Yes

livid fjord
#

Oh ok Yee

lapis sphinx
#

So gimme an example

#

Of another one

livid fjord
#

So (x+6)

lapis sphinx
#

Perfect

#

U just need 1 more

livid fjord
#

And (x-2)

lapis sphinx
#

Ayy

#

So what would be the final expression

livid fjord
#

Bro that took me too long to figure that out lol

lapis sphinx
#

Lol

#

Just take picture of what u wrote for final expression

#

Just to make sure u got it

livid fjord
#

I didn’t simplify yet

#

The image is taking forever to load

lapis sphinx
#

Does ur teacher demand u to simplify?

livid fjord
#

No he doesn’t

lapis sphinx
#

There u go

#

Just make sure

#

Those last two

#

Are under the division bar

livid fjord
#

Cool awesome

lapis sphinx
#

1 sec

#

U know desmos?

livid fjord
#

Yee

lapis sphinx
#

Try plugging it in to see if it’s right

livid fjord
#

I also got my TI-84

lapis sphinx
#

Just do desmos, faster

#

U should get

livid fjord
#

Shoot I wrote it wrong

lapis sphinx
#

It’s sideways

#

But that’s what u should get

#

Aight man I gtg

#

Pce

livid fjord
#

Thx so much man

lapis sphinx
#

Perfect

#

Cya

livid fjord
#

Cya

lapis sphinx
#

Tap on the places where ur supposed to have holes

#

It should say “undefined” for the y values @livid fjord

livid fjord
#

Oh ok

#

Thx

livid fjord
#

To find the oblique asymptote I think I’m doing the division wrong

uncut mulch
#

where's your quotient?
also there won't be an oblique asymptote here.

livid fjord
#

Ah okay thank you

wintry yacht
#

Where can I get help?

#

Anyone?

serene heath
#

your therapist

cedar pawn
#

Can someone do it fast to see if it's -inf.

#

I have -inf but in my textbook I have +inf

serene heath
#

,w lim as x approaches -inf of (sqrt(x^4-3)-xsqrt(9x^2-1))/(2x+7)

obsidian monolithBOT
cedar pawn
#

Sqrt(x^4) is always +x^2?

#

,w lim as x approaches -inf of (sqrt(x^4-3)+xsqrt(9x^2-1))/(2x+7)

obsidian monolithBOT
cedar pawn
#

It's inf, thought so I rechecked it and it's inf not -inf

humble pagoda
#

Sqrt(x^4) is always +x^2?
@cedar pawn yeah

cedar pawn
#

Same for any even exponent except for 2?

willow bear
#

no

#

only exponents that are multiples of 4

cedar pawn
#

So 6 can be + and -

#

Alrighty thx

sick seal
#

ive tried a multitude of things including whats in the answer box atm and i cant seem to pin down the answer

sick seal
#

12000-12000^(.8t) didnt work either

#

wait i figured it out

#

im thinking too hard

calm granite
#

it's the cubes of 3, 4, 5, 6

#

so the next one is 7^3=343

fiery wren
#

can someone check me

potent imp
#

huh

#

how can the cosine of any real number be -6

#

also thats not how the double angle formula works

#

cos(2x) is cos^2(x) - sin^2(x) not 2cosx

#

so ig the last one

fiery wren
#

i figured

#

i thought the values were the only ones wrong

#

what about

potent imp
#

yeah looks right

viscid thistle
#

ugh

#

someone help me with this plz

steel swan
#

should I skip pre calc

#

becaus eit seems dum

proud raven
#

@viscid thistle what made you say 65?

viscid thistle
#

@viscid thistle what made you say 65?
@proud raven 65 is the right answer

#

but idk how you get it

proud raven
#

yea me either ig

uncut mulch
#

properties of arc length

viscid thistle
#

properties of arc length
@uncut mulch great explaiantion

vapid gate
velvet granite
#

@vapid gate SOH CAH TOA

vapid gate
#

Are the two problem solving Sin and Tan @velvet granite

velvet granite
#

Well, you need to use the identities to solve for the missin sides

#

You have the angles 61, 90, and whatever 61+90-180 equals as your third angle

vapid gate
#

WELL i have x already but struggling witth y

velvet granite
#

once you have x just use Pythagorean theorem to find y

#

a^2 + b^2 = c^2

vapid gate
#

Thanks

velvet granite
#

np

vapid gate
#

8.87 us x

#

is

velvet granite
#

so 8.87^2+ 16^2 = y^2

vapid gate
#

I did it by using the sin found it much easier but thank you so much!

azure hedge
#

hello does anyone have answer key to math 1103 precalculus spring 2016?

uncut mulch
#

course content is different everywhere

rugged linden
#

hello, would $cos(\theta) = \frac{2}{3}$ not be a solution?

obsidian monolithBOT
rugged linden
#

since $180-\theta$ can be the angle between the x axis and the 6m vector as well, and from there we use the identity $cos(180 - \theta) = -cos(\theta)$

obsidian monolithBOT
rugged linden
#

if so, which one is "correct"? Do we solve for both angles and say hey I want an obtuse one so I'll choose the largest one?

quick mirage
#

@rugged linden Because the angle lies in a quadrant where the "x" value is negative, or where the angle > 90, (cos(angle) = x/r after all), the only value that would be appropriate in this case would be where x < 0, so 2/3 would not be a solution here

cobalt storm
#

How come I am not allowed to cancel out cosx

willow bear
#

same reason you can't cancel out the fives in $\frac{5-2}{5}$ to get $-2$

#

ok texit is dead

#

lemme just handwrite it

obsidian monolithBOT
willow bear
#

ah there it goes

quartz oxide
velvet granite
#

for a It says a has to be positive and for b a has to be negative
@velvet granite @quartz oxide

opaque vault
quartz oxide
#

@velvet granite ok but how do i make the graphs

velvet granite
#

Treat the years starting from1996 like x values

#

Number of adult animals like your y values

iron inlet
#

How do I find the maximum angle that I rotate f(x)=(3x^2+x+3)/(x^2+1) such that f'(x) is still a function, where f'(x) is the new equation after rotation?
I feel like it has something to do with injectivity, since the rotated function needs to pass the vertical line test
So I found that the function is injective on (-infinity,-1) U (1,infinity) and (-1,1), but I'm unsure how to use that info.

calm whale
#

probs try asking in a different channel

iron inlet
#

in what channel

violet knoll
#

Can anyone confirm this? I really feel like im missing something

full pagoda
#

should be correct

potent imp
#

yeah looks good

round quest
#

i got 8,28,88

humble cedar
#

how do i solve this

#

says minimum height of bridge over road is 4 but how is that relevant, the height is already 5

#

highway road is 10m wide which only gives 5 on each side, still dont know

willow bear
#

you're dividing by a quadratic, so the remainder is a polynomial of degree at most 1

#

so you have: P(x) = (x+4)(x-3)Q(x) + ax + b

#

where ax + b is your remainder, and a, b are constants that you need to find

uncut mulch
#

2 peeps with the same question #help-1

astral sedge
#

@uncut mulch the other person is actually posting my working out

#

I posted the question originally on a different sever titled "Homework Help"

#

and he posted my question to this server before I did

#

he then messaged me to join his server

echo wagon
#

This is a bizarre conspiracy, wth

astral sedge
#

ye lol

#

i can't explain it well enough

echo wagon
#

@uncut mulch

#

Pinging you because this is weird and funny

astral sedge
#

see, he is in both servers

echo wagon
#

Not cool tbh for him to copy Ram's help and pass it off as his own

astral sedge
#

yeah thats what i thought

#

:(

uncut mulch
#

copy pasta

#

word for word

#

wow

viscid thistle
harsh smelt
#

@viscid thistle so look

#

for example which % of students take a postgraduate degree?

#

👻

kind elm
#

t!goal claim

junior sable
#

What does it mean to raise something by a decimal? 10^4.640878 = 43740, but what does it mean to raise something by a decimal? To raise something by 4, sure, 10^4 is 10,000, but how do you wind up with a number like 43740, a very "unsquare" number?

lapis sphinx
#

so

#

for ur case

#

its 10^4.640878 right?

#

so 10^4.640878 is the same thing as

#

10^(4 + (640,878/1,000,000))

#

if we simplify that mixed fraction we get

#

10^ (4,640,878/1,000,000)

#

and then think about it like this

#

if 9^(1/2) is the same thing as √(9^1) with an index of 2

#

similarly

#

10^ (4,640,878/1,000,000) will be the millionth root of 10^4640878

junior sable
#

The beginner understanding of exponents as "this number multiplied by itself this many times" just won't apply anymore, huh?

lapis sphinx
#

i guess

junior sable
#

i see your steps, and thank you for that, but intuitively, 10^x in my mind should make a number that ends in many 0's. But you can put a decimal in x, any decimal into x and get any number you'd like out of it. How does that happen?

lapis sphinx
#

alright, so im not entirely sure abt why it happens, but we can also represent it utilizing logarithms

#

for example

#

10^x = 506

#

this means that log 506 = x

#

plug in into the calculator and u get 2.70415051684

#

then go back to ur original equation 10^x = 506 and plug in 2.70415051684

#

u should get 506

junior sable
#

i do. that's so weird.

#

10 multiplied by itself 2.7 times equals 506

lapis sphinx
#

yup xD

#

2.7 with all the decimals

#

those are key

junior sable
#

are those irrational numbers, those decimals?

lapis sphinx
#

i dont think so, given the fact that the answer comes out exactly to 506. and plus just think abt it, if u were to plug in a number with decimals that never ended, the final answer would never end either right? but the answer we have, 506, is a rational number that ends

#

i may b wrong, but thats what i think is right

junior sable
#

I'm having a hard time learning logs, exponents and square roots. They all seem like different ways of expressing the same thing. How did you learn all those identities, just with sheer willpower?

lapis sphinx
#

i mean, i just think about it like this. For squares, ur just multiplying a number/variable by itself. That was just memorization. For integer exponents greater than 2, i just remember once again ur just multiplying that number by itself however many times the exponent is equal to. For exponents less than 0, u just do the same thing as the exponents greater than 2 except u gotta take the reciprocal. For numbers and variables raised to the power of 0, its just memorization that the answer comes out to 1.

junior sable
#

square roots mb

lapis sphinx
#

o

#

sqrt of what types of values?

#

perfect squares? non perfect? variables?

#

but for logs its just memorization imo

#

the basic concept behind them

junior sable
lapis sphinx
#

i mean, that right there is just a bit of creative thinking

junior sable
#

i don't understand what's going on step by step

lapis sphinx
#

Step 1: problem. Step 2: tries to convert the denominator of that fraction into a value that can be inputted into the larger sqrt expression adjacent to it. Step 3 (tricky step): because u can combine sqrts, he puts them together under the radical. Step 4: simplify by factorization and by splitting up the fraction

#

Step 3 is a bit tricky

#

I'll give u an example

#

lets say u have (1/3) (sqrt(25))

#

in order to put the whole thing into the sqrt, one must change the 3 into the sqrt 9

#

since ur mutiplying, u can put 1 * ((sqrt (25)) / (sqrt 9))

#

once u have ((sqrt (25)) / (sqrt 9)), u can take out the square root from each individual number, and give it to the whole thing

#

u will be left with 1*sqrt (25/9)

#

that gives u 5/3

#

which, equals our problem from the beginning: (1/3) (sqrt(25)) = (1/3) * 5 = 5/3

junior sable
#

Whenever I multiply fractions, I multiply top to top, bottom to bottom. In step 2 they convert a denominator into a value that can be inputted into the square root. What's going on there?

lapis sphinx
#

if they didnt convert it, they wouldnt be able to input it into the sqrt

#

or u could also think abt it like this

junior sable
#

gotcha

#

i don't think i know how to simply that either

#

lets see if I can use microsoft math for this

lapis sphinx
#

U don’t need to

junior sable
#

that's a big help, thank you

lapis sphinx
#

no probs man

#

except what i did isnt the answer for the problem u saw in the video thing

#

its the sqrt of the final thing i got

#

but thats alrdy on the video thing so

junior sable
#

since all of it is under a sqaure root, would it be 2 root -1/x^3?

lapis sphinx
#

nah u cant separate it because its bonded by a "-" sign

#

if it was a multiplication, then u could bring out the 2

#

but with addition or subtraction, u cant

junior sable
#

gotcha

#

big thanks, thanks for taking the time and writing everything out for me

lapis sphinx
#

yea np

#

it was a good review tbh

cobalt storm
#

Is this correct?

#

Like is this allowed

#

Am I able to divide both sides by cosx

willow bear
#

not without a bit of extra work you aren't

#

as-is, you lose a whole bunch of solutions

#

yes

cobalt storm
#

But like algebraically is it correct?

#

Am I allowed to divide both sides by cosx

lapis sphinx
#

What’s the original problem

#

@cobalt storm

uncut mulch
#

if this is a solve question, you shouldn't divide by stuff that could be 0

#

instead consider factorisation

cobalt storm
#

cosx = 2sinxcosx

halcyon chasm
#

i'm having trouble solving $\cot(2\pi t)=-1$

obsidian monolithBOT
halcyon chasm
#

anyone? i will post what i've tried if it encourages the helper

#

nvm solved

serene heath
#

uhhh

viscid thistle
#

Uhh

serene heath
#

<@&268886789983436800> hi

viscid thistle
#

Dang you sniped me

serene heath
#

forgot i can delete stuff

viscid thistle
#

Lmao

#

(for the mods seeing this, a guy posted an innapropiate pic and now it's deleted)

severe verge
#

yea i banned em

misty ocean
knotty echo
#

take a look at $sin^2x - 6sinx + 9$

obsidian monolithBOT
knotty echo
#

what do you notice about the form of that expression

misty ocean
#

its ax^2+bx+c

knotty echo
#

yes it is quadratic, therefore try factoring

misty ocean
#

i did but i end up with sinx-3

#

and idk how to make that into (1-3 cscx)/cscx

knotty echo
#

since the right side is all in terms of cscx, then use your reciprocal identities to set the left side in terms of cscx

misty ocean
#

ok now i got (1-3)/cscx but where does the top cscx come from?

knotty echo
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ok good so $\frac{1}{cscx} - 3$

obsidian monolithBOT
knotty echo
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combine these 2 terms

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(1-3)/cscx is not correct

misty ocean
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ohhhhh

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ok idk why i put the -3 up there

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thx

knotty echo
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np

hallow bison
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is the answer for that question this?

idle moat
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how do you do the first step?

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i dont understand what he did with the denominator

thin pulsar
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Hello

viscid thistle
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Hi can someone check if my answer is correct? I got N 58.77 degrees E.

uncut mulch
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seems you got the direction wrong

viscid thistle
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Would it be S W?