#precalculus

1 messages · Page 18 of 1

frigid trout
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Ohh you’re right

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Thank you Saul

jaunty crow
viscid thistle
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Is there a way to factor this by hand or by calculator this is the only part i keep getting confused on for inequalities with polynomial functions and its really really pissing me off cause i could solve it online but i don't know how to do it by hand or by my own doing

normal coral
normal coral
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you are in the pre calc channel

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pre calc

gaunt sand
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And factorise it

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x^2(x-4)

viscid thistle
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What happens to the x³

gaunt sand
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to it

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if u expand, u do x^2 * x

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and x is just x^1

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so x^2*x^1 = x^2+1 = x^3

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indices rule ^

viscid thistle
marsh condor
jaunty crow
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Well the homework was already due

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But I didn't understand it

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So id appreciate the help

marsh condor
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Do u know how to calculate the derivative?

jaunty crow
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Yea

marsh condor
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Okay that’s the bulk of the problem

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A horizontal line has a slope of 0

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Therefore f’(x) = 0

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Then you must solve for x

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9e^x(sin(x)+cos(x)) = 0

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When do sin and cos have + and - outputs

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2nd and third quadrant

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But the domain is 0 to pi

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So only second quadrant

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In the second quadrant they have the same |output| at 3pi/4

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So that’s that

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Then u have to plug that value into the original problem

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To find the y value of f(x)

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I assume ur allowed to use a calculator

marsh condor
jaunty crow
jaunty crow
marsh condor
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Sin and cos have - and + values in the 2nd and 4th quadrants

jaunty crow
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Yea

marsh condor
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They’re equal -cos(x) = sin(x)

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At 3pi/4

jaunty crow
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Oh

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Yea

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Makes sense

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Thnx

warped cipher
warped cipher
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x^2-4 has a perfect square

marsh condor
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It’s factorable but it isn’t a perfect square

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(x-4)(x+4)

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Subtraction of squares rather

warped cipher
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meant it has a perfect square in factorable not just only a perfect square

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whats the difference anyway

marsh condor
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The two terms r perfect squares

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Technical stuff lol

warped cipher
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some people still call it a perfect square in factorable lol

warped cipher
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try khan academy if you haven't

digital mirage
warped cipher
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apply l'hospital's rule

scarlet vine
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i so regret not studying precalculus before getting into cal AB bruh

scarlet vine
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i would prefer to use either the factoring method or rationalization instead of that ;-;

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im not really sure why tho

pine geyser
warped cipher
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0/0

normal coral
warped cipher
normal coral
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cause most places I have seen, it is taught in calc 1

warped cipher
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it depends which country honestly

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but I get calc 1 taught in high school

normal coral
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ah ok

warped cipher
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not really actually calc but they teach l'hospital rule at least

scarlet vine
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actually

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i havent learned about that rule

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but i know the form tho

wanton marsh
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Any one that would be willing to tutor? Can pay for time spent of course.

dawn osprey
faint igloo
slim steppe
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You've also got online resources to use for FREE

wanton marsh
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Ah, my apologies. @faint igloo

long tulip
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<@&286206848099549185>

hushed loom
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Did this help?

lean nest
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both of these are because fractions exist

frozen dirge
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" if there is a limit find it "

dawn osprey
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Well, from either side (negative or positive) we are approaching some value at x =1

frozen dirge
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ye

dawn osprey
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you'll be infinitely close to x =1 which should result in y =(?)

dawn osprey
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maybe that wasn't a good way of explaining it, think of it like this...

what value is the function approaching if we plug in x =1?

frozen dirge
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like according to the equation

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is there a method to do this

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im not asking for the straight up answer but i wanna know how its done

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im a visual learner

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1^2 + 3 = 4 right

dawn osprey
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Right, the limit value of a function does not depend on how the function is defined at the point being approach (whether or not its not part of the graph)

frozen dirge
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so 4 ?

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ight

dawn osprey
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right

frozen dirge
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i got a few more questions

dawn osprey
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You can ask them

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I might not be able to answer them tho, I gotta go soon

frozen dirge
frozen dirge
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sorry its that way

dawn osprey
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okay, what about this question

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I won't just do your hw if thats what you're getting at 😭

frozen dirge
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not the answer

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im tryna understand

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its that if the value of the given quantity exists and if it does find it

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that

dawn osprey
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yea, so limits are asking what value is being approached, they differ from per say f(0) in that f(0) is asking the defined value

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so in this case f(0)= 4

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but the limit as x approaches 0 will be different ( depending on what side you're coming from)

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If that didn't answer your question, try watching a video like https://youtu.be/7Q2HwTHcxA0?si=XAyux28wp_nBvCkG and see if that helps explain

This calculus video tutorial explains how to evaluate limits from a graph. It explains how to evaluate one sided limits as well as how to evaluate the function using graphs. The graphs include points of discontinuity such as holes, jump discontinuities and infinite discontinuities such as vertical asymptotes. Horizontal asymptotes are include...

▶ Play video
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I gotta go for now tho, hope you can get it sorted out

thorn creek
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that looks more like a chart for a sportsball play than it does a math problem

dawn osprey
# frozen dirge i seen this bru

If you’re asking how to answer the question from what I can tell it would be:

If (e) is undefined, explain why it has no value. In this case it’s because there was a removeable discontinuity

thorn creek
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in that example f is undefined at 2 because it's simply not defined at 2

dawn osprey
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Yea

thorn creek
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whether a function has a limit at x has nothing to do with whether it's defined at x

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it has to be defined on a deleted neighborhood of x, but not necessarily at x itself

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and in this case f is defined on a deleted neighborhood of 2

dawn osprey
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Yea, maybe removable discontinuity wasn’t the right word, but I don’t think he really has a grasp of what lim x->n is asking

thorn creek
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no, you're right, it is a removable discontinuity

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the key takeaway from that exercise is the understanding that the limit of f at x has nothing to do with what f does at x itself, only on what f does near x

dawn osprey
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Yea that’s what I was trying to say with the “a limit is the value being approached”

thorn creek
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the function f(x) = { 1 if x is an integer, 0 otherwise } has limit 0 at every real number

dawn osprey
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My bad I thought you were saying something else

thorn creek
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and is discontinuous at every integer and continuous everywhere else

whole island
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$x \neq 1$

frozen dirge
obsidian monolithBOT
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Tank_Driver011

whole island
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The function is discontinuous -- do you know which type of discontinuity it is?

whole island
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we have removable, infinite, and jump.

frozen dirge
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oh yea i know jump

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must be removable then

whole island
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removable - there is a hole
infinite - vertical asymptote
Jump - a split in the graph

frozen dirge
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so its jump

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coz its a split

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a long split tho

whole island
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an asymptote is a line that the graph never touches.

frozen dirge
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ah bet

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dude its a jump

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the picture if just tiltied 90*

whole island
frozen dirge
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no no

frozen dirge
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i already found that one!

whole island
brittle ice
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the notion "getting closer and closer" can be made precise using convergent sequences

whole island
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oh!!!

frozen dirge
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oh bet

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ye i see what ur saying

whole island
obsidian monolithBOT
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Couldn't find an attached image in the last 10 messages.

whole island
obsidian monolithBOT
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Couldn't find an attached image in the last 10 messages.

frozen dirge
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hol on

obsidian monolithBOT
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Tank_Driver011
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

frozen dirge
obsidian monolithBOT
whole island
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25 or 26? Both? let me explain 25 and you complete 26.

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a. f(1) - you plug in 1 for x and look for y (look at the graph at x = 1, notice it is a hole/DOES NOT EXIST, therefore, the point that is circled in is the answer at (1,2)

b. limit as x approaches 1 for the function f(x): approach x=1 (on graph) from the left and the right, notice how the graph splits (from the left, you are above the right piece of the graph). Since the right and left do not give the same answer (right gives (1,1) and left gives (1,3), then the limit as x approaches 1 DOES NOT EXIST.

c. plug in f(4), find the point on the graph -- it has a hole at this point so it is DNE

d. limit as x approaches 4 for the graph f(x) meets at the same point (both left and right), it is continuous, therefore as x approaches 4, f(x) approaches 2.

REMEMBER
f(a) is different from limit x --> a f(x) -- the limit approaches some value, f(a) is that point and if it has a hole for f(a) then it does not exist but if hole is for limit, you write the value it approaches. see above for explanation

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@frozen dirge

frozen dirge
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wait

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im eating rn ill look into it

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thanks!!

rain palm
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I'm struggling on this question could someone please explain? I tried my best on the answers

floral horizon
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guys, im just starting limits, was wondering if someone could answer this cus i havent read it yet. Whats a derivitive in definition? WHats a limit? if someone could ping me or reply thatd be cool, its been a childhood question of mine.

viscid thistle
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Can |x| <_ -4 be represented using a number line?

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can anyone help me factor this i dont know whrere to begin lol

lapis ravine
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hii, new to the server i have a question...
is the coordinate of the focus of a parabola that opens to the left (a, 0) or (-a, 0)?

dim goblet
viscid thistle
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can anyone solve this polynomial inequality I know how to do everything im just confused on the answer

sour bolt
distant ledge
digital mirage
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can u guys suggest me any video to learn Riemann Integra in depth ?

tepid escarp
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Hi guys, our teacher wants us to make a 3D model of all the conic sections. Any ideas or suggestions?

hushed sphinx
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Sounds like a cool project. I think I'd try to make it work with office paper for the cone and stiffer cardboard for the plane that intersects it.

thorn creek
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i was thiunking 3d printer, but yeah that's probably less work

digital mirage
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in 1 one both end points are not meeting , but in 2 both end pints are meeting , how is this possible , in 2 one for one value of x how two values of y are possible ?

stark nova
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f(x) = (x-2)(x-3)

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im going crazy i have tried breaking it and removing the roots but nothing

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its hs math and i havent done derivatives yet so please no derivatives

trim cape
stark nova
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i know thats the only way to solve it but im kind of stuck

trim cape
stark nova
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i broke the 2 and multiplied the one by /x+6 and the other with /x+1 -1

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so its x+6 -x with the denominator being differnet of course

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and from then on i tried making it x-3 +9 and getting rid of the x-3

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but it doesnt really work

trim cape
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can you send a picture?

stark nova
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wait i need to write it because i got rid of the other

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1 minute

trim cape
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ah you split it up

stark nova
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yeah

trim cape
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i wouldn’t do that

stark nova
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but if i do it without splitting it it will end up with a /x+6 * /x+1

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and i cant remove it unless i break it again

trim cape
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then you can multiply by the conjugate

stark nova
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then i will end up with /x+1

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you mean to then split and get rid of it or

trim cape
stark nova
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wait ill try it

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without splitting

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ok

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so now its 2x -2/x+1

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should i do congujate agian

trim cape
stark nova
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but isnt it x+6 -(1+/x+1)^2

trim cape
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yes

stark nova
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so its x+6 -1 -2/x+1 + x +1

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so -1 and 1 goes away and

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oh the 6

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ok ok

trim cape
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distribute the minus to all terms

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its -x-1 at the end

stark nova
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am i an idiot?

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yes

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ok so its -2 -2/x+1 right

trim cape
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you forgot the 6

stark nova
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-4 -2/x+1

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so do i congujate again

trim cape
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Well its +4

stark nova
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thats true

trim cape
stark nova
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oh oh oh

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I want to give you a kiss

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but thanks

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yeah now it comes out

trim cape
void mesa
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Why is thins wrong?

digital mirage
pine geyser
void mesa
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it's wrong because it's actually a floor function

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stupid ass website didn't display it properly lmao

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thought it was a absolute value notation

magic geode
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"with vertex at (5,4) and focus at (5,-1)" how do i find the properties? C, V, F, D, A, LR, 1/2 LR, L, R?

pine geyser
void mesa
void mesa
last root
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Why this integration = -1?

west citrus
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Cauchy integral definition of integral

pine geyser
calm fractal
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anyone know what these notations mean

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or symbols rather

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nvm simple google search explained it for me

wicked knot
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i need help with this thanks so much in advance <33

strange perch
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yo i need help in my pre calc class

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plz add me if you can

wooden brook
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$$I_{n} = ∫(x^{2} + 1)^{-n} dx$$

Show that

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

obsidian monolithBOT
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KnightOnF1 ♘

wooden brook
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Reduction formula

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But how

iron spoke
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$\sqrt{(2^n+3^n+4^n)}$

obsidian monolithBOT
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xxOctavianxx

willow bear
#

what are you asked to do with it

iron spoke
willow bear
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this is not an equation

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you cannot solve for n

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!original

tender questBOT
#

Please show the original problem, exactly as it was stated to you. A picture or screenshot is best.

If the original problem is not in English, then post it anyway! The additional context might still help helpers help you. Do your best to translate.

mint forge
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This is the precalculus channel

iron spoke
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maybe

iron spoke
mint forge
iron spoke
willow bear
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because to me it looks like "determine those n in N for which the expression is rational"

thorn creek
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whee number theory

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there's a well-known proof that 2^n + 3^n is never a perfect square, so i suspect a similar strategy to that in that well-known proof would work

onyx lotus
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i have a question why doesnt the 3x get cancled out?

summer ruin
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because it's a typo

gray maple
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What up mathletes

normal compass
#

yo am struggling with functions and two-dimensional coordinates, internet doesn't give much better explanation, i think y'all students can help me (?)

iron spoke
willow bear
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no and i did not really care much about this problem in the first place

empty trellis
#

Can anybody help me with a question? I asked ChatGPT this question and told me that all values of k work.

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If the function f is defind by f(x) = 2x + k and the function g is defind by g(x) = (x-5)/2, for what value of k is f(g(x)) =g(f(x))?

twilit quartz
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2x + k?

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@empty trellis

empty trellis
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yes

twilit quartz
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@empty trellis i think its + 5

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for k

empty trellis
#

can u explain plz

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🙏

twilit quartz
#

Sorry if i dont explain this well, im still learning functions myself. So i just placed a guess, and put 5, and tested if it would be true, and wrote it down.

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g(x) at 10, would be 2.5, and 2.5 at f(x), would be 10, and then i did it again

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f(x) at 10 would be 25, and 25 at g(x), would be 10

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both answers come out to 10,

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the = 10 in the picture isnt the answer for the functions btw, its for the functions below i just wrote them there

empty trellis
#

Tysm

twilit quartz
timid agate
#

why won’t this work?

slim steppe
timid agate
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still doesn’t work

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desmos says «Integration bounds can’t depend on the integration variable ‘x’»

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but it works with y

slim steppe
#

Desmos only calculates the definite integral with numerical bounds

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Doesn't calculate some integral that has variables as bounds

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@timid agate ^^^^^^

thorn creek
#

desmos is right, the variable of integration cannot be a bound of the integration

thorn creek
#

you can get pretty complcated, too:

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the issue is that you can't have the same variable in the bounds as the variable of integration because it's ambiguous what you mean

warped cipher
#

bro is too good

slim steppe
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It doesn't fully compute the anti-derivative function for me

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Just shows me what it is

thorn creek
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yeah, i didn't ask it to do that

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but that wasn't the point i was trying to make; the claim was that desmos couldn't graph curves defined by a integral having a variable bound, and that's not true

cursive crag
#

my fellow precalc students

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what is up

short saffron
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Suppose there is a function $y(x)$ satisfying $\frac1{1-x}\le y(x)\le \tan(\frac{\pi}{4}+x)$. For which $x$ is this function bounded?

obsidian monolithBOT
#

sunside

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sunside

short saffron
#

Never mind my question.

strange perch
#

who got the answers

frigid trout
#

move 3 on other side and divided by -3 to get x by itself

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then you flip the sign since youre dividing by a neg

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-3x < -3

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= x > 1

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so x values have to be greater than 1 and they cant be one so open circle facing right if im not mistaken

hexed apex
#

can someone help me with this

summer ruin
#

properties of logarithms

restive berry
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lol

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but i see someone else has already answered

jagged vine
#

hey I just wanted to know if im doing this right or not bc I have been trying to teach myself diff ways but I got 2 diff answers

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i got f^-1(x)=7/3x+1/3

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but tried a diff way n got f^-1(x)=3/7(x-1)

radiant kite
thorn creek
#

i have no idae what proper inverse function notation is

thorn creek
jagged vine
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i just dont understand proper inverse function notation

thorn creek
#

i don't know what that means

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it's something your textbook or your instructor has defined, it has no standard meaning of which i am aware

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if i do the "replace f(x) with y, interchange y and x, and then solve for y" i get "y = (-1/3)*(x-7)/x"

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you then replace y with f^-1(x)

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using a computer algebra system: ```
sage: solve([y==7/(3x+1)], x)[0].subs([x==y,y==x])
y == -1/3
(x - 7)/x

hexed apex
#

can someone help me with b)? i dont know how to do it

thorn creek
#

i don't like that question. a vertical asymptote is not merely a point at which the function is undefined because it involves a division by zero

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take the function f(x) = { 0 if x is an integer, 1 otherwise }

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1/f(x) is { 1 if x is not a integer, undefined otherwise }

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i would not consider 1/f(x) to have a "vertical asymptote" at each integer even though 1/f(x) is undefined at each integer because the definition involves a division by 0 at each integer. for x to be vertical asymptote, the function should approach infinity on a deleted neighborhood of x, but 1/f(x) is bounded on every (sufficiently small) deleted neighboorhood of any given integer

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however, you'll have to review the definition of "vertical asymptote" that your text or instructor has given you and apply that definition, which might not agree with my sense of how that term should be defined

jagged vine
#

anybody have a site that can do this? mine just wont give a maximum lol

thorn creek
#

desmos may provide insight here

proper barn
#

hey, im a precalc honors student in unit 2 rn. the first unit was the unit circle, and i completed all quizzes and tests with relatively good scores. onto unit 2, i unfortunately missed many days due to unforeseen circumstances, and am really behind and need help learning the content. i have a quiz on monday, and the unit test on tuesday. the unit is called graphing trig functions, and we are not allowed to use any form of calculator under any circumstances. if someone can devote some time to helping me learn this unit, that would be really helpful

viscid thistle
#

can anyone find a video on where i can learn about this i just don't understand ;/

gaunt sand
#

Maybe someone here can assist

viscid thistle
#

although if anyone can can someone check one of my problems for work its x int

viscid thistle
#

curious if its -4 or none

lunar viper
#

how would i do this?

junior heart
#

Nobody in my class can solve this, so now I'm trying to get help elsewhere. The answer list says a cubic function with negative a-value, with local maximum at x=4 and local minimum at x=-2, if it is to any help:

A function which is valid with the restrictions given below:

thorn creek
#

those are some big parentheses

glad nova
#

hey guys, I was wondering if anyone had some good resources for calc stuff?

hexed apex
#

is this right? i know that at x=7, the slope is 0 and idk whether i should include that point

summer ruin
#

f'(x) = 0 is not f'(x) > 0

hexed apex
#

yes i know

summer ruin
#

what's the problem then

hexed apex
#

for example, for 5 < x < 7, 7 is the endpoint of the interval and since its the > and not the ≥, i am wondering if its correct to select that as the answer for f'(x) > 0 since the 7 is not included in the interval but just stops there right?

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or am i wrong

summer ruin
#

it is correct

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you should check your other answers though

near viper
#

help!

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how tdo i solve

tall lion
#

p=2/5 ?

viral mesa
wheat radish
novel spear
# near viper

make a least common denominator so
(6(p-3)+p*(p+3))/(p+3) * (p-3)

distribute
6p-18+p^2+3 / (p+3) * (p-3)

combine like terms
9p-18+p^2 / (p+3) * (p-3)

multiple sides by denominator
9p-18+p^2 = (p+3) * (p-3)

simplify right side
9p-18+p^2 = p^2-9

subtract p^2 from both sides
9p-18=-9

add 18 to both sides
9p = 9

divide both sides by nine
p = 1

viscid thistle
# radiant kite

divide acosx-bsinx/bcosx+asinx by bcosx in both numerator and denominator

native steppe
#

is 7*1/3x+1

hoary leaf
#

help can someone explain how it's C (I made an equation g(x)-1/2f(2x) but the values i plug in don't work)

radiant kite
#

help

novel spear
#

i typed that shit

warped cipher
tender questBOT
# novel spear bruh

As a helper, please do not give out answers that could be copied as a homework solution. Have the student work through the problem themselves and guide them along the way.

novel spear
#

@warped cipher what does !nosols mean

warped cipher
#

read it

novel spear
#

no solutions

#

crazy

warped cipher
#

it's shortcut for no solutions or answers I think

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it's against the rules

novel spear
#

interesting

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why’s it against the rules

warped cipher
#

idk tbh

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but it could many people just want others to do their hw without understanding how they did it or some of them just wanna cheat during the quizzes/tests without understanding it as well

novel spear
#

well mb i didn’t know

exotic void
#

hello can anyone explain why this is wrong

thorn creek
#

the first one is marked wrong because you omitted a repeated root

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and in the second one you only gave one of the three real roots, the polynomial has two other real roots

viscid thistle
#

what are you doing to solve it

sweet agate
restive dome
#

does anyone have a trick for solving rational functions with absolute values?

radiant kite
#

then eventually i get tan^-1(x+1)=tan^-1x

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which gives no solution

faint anchor
#

I need some clarification about inequalities. If I have the following inequality:

1/2 * X <= Y <= 2 * X
Am I allowed to look at the upper bound and lower bound individually and produce bounds for X? Like so:
1/2 * X <= Y gives X <= 2 * Y
and
1/2 * Y <= X
So we conclude that X can not be bigger than 2 * Y or smaller than 1/2 * Y?
Thanks

sweet agate
plush sparrow
acoustic heron
#

yo how can i do hyperbolas my prof didn't teach us how but having a midterm tomorrow

warped cipher
acoustic heron
warped cipher
# acoustic heron i think it prolly is?
\sethlcolor{Orchid}
\subsection*{$\bigstar$ Reciprocal Function: $f(x) = \frac{1}{x}$}
\begin{minipage}{0.5\textwidth}
\begin{tikzpicture}
    \begin{axis}[
        grid=both,
        axis lines=middle,
        xmin=-3, xmax=3,
        ymin=-2, ymax=2,
        xlabel={$x$},
        ylabel={$y$},
        ]
        \addplot[RoyalPurple, thick, domain=-3:-0.1] {1/x};
        \addplot[RoyalPurple, thick, domain=0.1:3] {1/x};
    \end{axis}
\end{tikzpicture}
\end{minipage}
\hspace{1cm}
\begin{minipage}{0.4\textwidth}
\centering
\begin{tabular}{cc}

$x$ & $f(x)$ \\

-3 & -0.33 \\
-2 & -0.5 \\
-1 & -1 \\
1 & 1 \\
2 & 0.5 \\
3 & 0.33 \\
\end{tabular}
\end{minipage}
The reciprocal function $f(x) = \frac{1}{x}$ has \hl{two hyperbolas} in the 1st and 3rd quadrants. As $x$ approaches 0 from either side, $f(x)$ approaches $\pm\infty$.
obsidian monolithBOT
#

Akira 🍉

warped cipher
#

this you want?

acoustic heron
#

nope this is the one im talking about

#

only horizontal and vertical

warped cipher
#

can't tell if this is absolute value or parabola

#

nah that's looks like reciprocal function

viscid thistle
#

hyperbolas?

#

is mathematical induction helpful in calclus or pre-calc?

#

generally no

viscid thistle
viscid thistle
#

just curious

viscid thistle
viscid thistle
#

don't worry about proving anything if it's your first time learning calculus

#

just build intuition

viscid thistle
viscid thistle
#

mean value theorem

#

i see, but i do have a question, why do we use continuties? and what is the right way to do them?

#

can anyone help with this

viscid thistle
#

if a curve is discontinuous, you may not be able to apply certain tools

#

limits are used to determined continuity at a certain point

warped cipher
misty saffron
#

nice

soft copper
#

can anyone help me with the letter c

viscid thistle
# soft copper can anyone help me with the letter c

lets say that
there are two concentric squares where the bigger one has a side of S and smaller one has side of S-1,
The shaded area clearly corresponds with the function A(S-1) as the shaded area tends to show the smaller square
Similarly the sum of the area of of the unshaded region and shaded region corresponds with the function A(S)

#

so with the shaded area A(S-1) will correspond

#

the other expression i think corresponds to the sum of the unshaded regions

#

@soft copper i suppose this must be oyur answer

woeful jungle
#

nice

digital garnet
#

How do you find the phase shift?

paper hearth
#

Any of you guys wana help my dumass pass the class?

#

im honestly confused on some stuff some explaining might help

potent willow
#

i can help!(i cant i didnt learn anything from precalc)

warped ridge
exotic void
#

Can someone explain how (x-4)^2 +1 is facted to (x-4+i)(x-4-i)

vapid plaza
#

+1 can be written as -i^2

exotic void
#

then why is it +i and then -i?

summer ruin
#

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

exotic void
#

oh

#

i think it's clicking

#

thank you

digital garnet
warped ridge
#

Aight

nova cargo
viscid thistle
twilit quartz
#

#help-23 sorry guys, but nobody is responding, if u wanna look at this, tyvm

thorny heart
#

can anyone teach me basic integation and special integrals?

slim steppe
vapid coral
thorny heart
slim steppe
quartz leaf
#

hi i had a question about chain and product rule

#

like say you had a problem

#

is there any scenario where you could use product or chain rule to differentiate it and get the same answer?

stark stream
#

i'm assuming u are talking about a question like (2x-3)^2

#

in this case you can probably use both and get the same answer

#

chain rule will give you 4(2x-3)

#

and so will product

golden frost
#

How do I figure out the values on the sides and how their placed

willow bear
sick trail
#

hey how do i differentiate x^3+4/x

#

where do i start

inner cobalt
#

um

inner cobalt
#

d/dx of x^3 + d/dx of 4/x

rain marten
#

yeah

inner cobalt
#

then

rain marten
#

then 4/x is rewritten as 4x^-1 through index laws

inner cobalt
#

power law it

rain marten
#

yeah

inner cobalt
#

yas

rain marten
#

d/dx (x^n) = nx^(n-1)

#

anyway i came to this channel so i could ask a different question, maybe its a bit too advanced for this channel but im putting it here because im not at university yet idk

#

i was thinking about factor theorem and how if f(n) = 0 then (x-n) is a factor of f

inner cobalt
#

o

rain marten
#

& maybe that rule only applies to polynomials but i thought "what about sin"

inner cobalt
#

sin

rain marten
#

yeah

#

this is where it gets wacky

inner cobalt
#

wat fnction

rain marten
#

because sin(0) = 0 so that implies that x is a factor of sin(x) right?

#

but then there's also sin(pi) and sin(2pi) and so on

inner cobalt
#

yeah

#

but

#

graphically

#

sin isnt the same as a polynomial

#

so you cant really

#

classify it that way

#

and u cant really factorise it as well

rain marten
#

so does that suggest that sin(x) is an infinite product of (x-0pi)(x-pi)(x-2pi) and so on??

inner cobalt
#

it could be

rain marten
inner cobalt
#

oh yeah

#

i forgot about maclaurin series it turns the sin into

#

well yeah

rain marten
inner cobalt
#

that was what i was thinking

#

cause

rain marten
#

so what do you scale it down by? infinity? since its infinitely big polynomial

inner cobalt
#

isnt it only regarding the x value

#

s

rain marten
#

wdym

rain marten
#

ill get desmos to show it

inner cobalt
#

the first function

rain marten
#

the red polynomial is wayyyyy too big but if you scale it down by like 1000 it kinda looks like sin a bit

inner cobalt
#

just the roots of the equation

#

sin(x)

rain marten
#

thats another problem also because the max min points arent all the same

inner cobalt
#

yeah

#

cause its a polynomial

rain marten
#

like is that a problem that just solves itself as you add more terms or

#

idk

inner cobalt
#

since the degree of x is increasing each time

rain marten
#

heres more terms scaled down more

inner cobalt
#

close

rain marten
#

you can see it stays closer for longer

inner cobalt
#

i feel like it would be an approximate not

#

exactly

#

but i couldnt be sure

rain marten
#

so if you have loads of terms like infinitely many of them would it just be sinx eventually

#

idk if im just spouting nonsense here im quite ill

inner cobalt
#

not sure bout that

#

since a polynomial term has finite number of terms

#

and the sinx function has infinite number of roots

#

im afraid sinx cant be expressed as a polynomial

#

not possible BUT

#

a sequence may work

#

they are periodic

rain marten
#

so you're just wrong there

#

because its an infinitely long polynomial it can have infinite number of roots

#

and thats what im thinking about also

atomic goblet
#

Anyone that’s good at trig

#

I need help on this one question

tough veldt
#

I have an incoming exam of a math course two weeks till now, The course is about differentiation: rate of change, function of a function, implicit function to differentiation of trigonometric and inverse trig function. I don't know this math course. I want to ask for help if anyone has a simplified documentation for this and Youtube channels suggestions that explain the concept. Please, it will be a great help for me. blobsweat

river hearth
# tough veldt I have an incoming exam of a math course two weeks till now, The course is about...

check out 3b1b's videos on the essence of calculus (theres like 12 u probably dont need to see them all)
https://www.youtube.com/watch?v=WUvTyaaNkzM&list=PLZHQObOWTQDMsr9K-rj53DwVRMYO3t5Yr

What might it feel like to invent calculus?
Help fund future projects: https://www.patreon.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Special thanks to these supporters: http://3b1b.co/lessons/essence-of-calculus#thanks

In this first video of the series, we see how unraveling the nuances of a simp...

▶ Play video
tough veldt
radiant kite
#

,help

obsidian monolithBOT
#

A brief description and guide on how to use me was sent to your DMs!
Please use ,list to see a list of all my commands, and ,help cmd to get detailed help on a command!

radiant kite
#

,list

obsidian monolithBOT
#
My commands!

Use ,ls to obtain a briefer listing, and use ,help <cmd>to view detailed help for a particular command, or ,help to view general help.

If you still have questions, talk to our friendly support team here.

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View or set meta-information about me.
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feedback: Send feedback to my creators

sick trail
#

how would one work out question 5a

#

and question 6

zinc fulcrum
#

bro what kek

vapid plaza
#

Bro is writing hieroglyphics

willow bear
#

what the fuck does this mean

mint forge
#

<@&268886789983436800> sorry for tags

#

How much raid in this server

solar olive
#

well

#

an infinite product

inner cobalt
#

Which isn’t

solar olive
#

okay, u could argue about its taylor series being a polynomial representation of it

willow bear
#

what is infinity minus 1

#

where did you see this

#

photo?

delicate shore
#

Guys help me solve this im stuck on a step

#

This is differentiation byw

hushed sphinx
#

Doesn't look like precalculus.

dense mango
#

can someone PLEASE show me the steps of differentiating this??

hushed sphinx
#

Doesn't look like precalculus either.

dense mango
#

so what is it

#

calculus?

hushed sphinx
#

Yes.

dense mango
#

ok I'll change channels then

frosty laurel
#

yall am abt the rip my brains out rn

#

can someone help me solve this

#

oh nvm this is preclc

slim steppe
#

Then just use u sub if you'd like

frosty laurel
#

ty bri

#

broo

#

😭

frosty laurel
fiery sinew
#

Can someone please explain how to do these the answers are highlighted

#

I did this for number one but idk it just doesn’t seem right

#

Even though it got the answer

summer ruin
#

what do you think about inequality e^(3x) >= -1

hushed sphinx
#

2 must be a typo or something extremely weird going on.

fiery sinew
#

Oh yeah sorry it was arcsin I miss wrote the question now it makes sense

fiery sinew
summer ruin
#

I think you can say more, but sure

fiery sinew
fiery sinew
summer ruin
#

yes

fiery sinew
#

Ok thank you

rain marten
#

i just realised that e^x has no roots, and e^x = 1 + x + ½x² + ⅙x³ + ...
does this mean that this is a polynomial with no roots???

hushed sphinx
#

No, because a "polynomial" by definition has only finitely many terms.

viscid thistle
#

like let e^-x/2=t

#

then find the value of dx

#

substitute it

#

and also

#

take log both the sides

#

will help u

rain marten
strong verge
#

can someone quickly tell me what transformation -f(-x) is ? bc how is it a reflection in both axis

#

if u multiply it out its just f(x) which is the og function but thats not the answer

hushed sphinx
#

You can only "multiply it out" like that if the function happens to be odd.

#

I don't think it has a name. It's something you can do with a function. Rotates its graph 180° around the origin.

frosty laurel
fallen sequoia
#

how did they get to costheta + isintheta? i understand the magnitude |z|

#

i must have forgot my trigonometry

#

i'm struggling to understand why the x coordinate is given by |z|cos theta lmfao

hushed sphinx
#

(cos(theta), sin(theta)) is the standard parameterization of the unit circle in the R^2 plane, this just expresses that as complex numbers instead.

fallen sequoia
#

huh i see, i think i understand

#

this has always been a concept that i've overthought

hushed sphinx
#

In other words cos(theta)+i sin(theta) is the complex number corresponding to where the point where the fat arrow in your diagram crosses the unit circle.

fallen sequoia
#

hmm ok, thx

viscid thistle
#

anyone familiar with this theorem

normal coral
viscid thistle
#

this is about finding roots

worthy bridge
#

ok thug

#

how is my answer wrong tho, my teacher is fucking me over

#

bro what.. i asked for help not a life story

#

nice one

uncut mulch
#

"standard form" is ambiguous
in this context, they probably mean vertex form

normal coral
obsidian monolithBOT
#

saddayyy_

viscid thistle
#

but it would still be really off to just refer to calculus whenever you see a derivative signs i suppose

#

cause many other math topics use the concept of derivative

#

it is simply introduced in calculus formally

normal coral
viscid thistle
normal coral
#

ah ok

viscid thistle
#

related theorem taught is one called descarte's rule of sign, which I think is very similar

#

also about finding real roots with different amounts of sign changes in a polynomial

vast quartz
normal coral
#

@viscid thistle if u don't mind me asking, are u in the us, or international?

normal coral
#

ah

#

so I would put that in #calculus as that does involve some differentials that are not taught in the normal us precalc curriculum

#

or in the help forum

#

when in doubt

viscid thistle
#

ok

novel sparrow
lunar viper
lone yoke
#

Hi can you guys help me with this?
1.How is the equation of an ellipse determined when the foci and vertices are given? (Note that the term "vertices" refers to the endpoints of the major axis.)

  1. Is it possible to determine the equation of an ellipse when the coordinates of the endpoints of the major and minor axes are given? If so, explain how.
remote mesa
#

Math software is literal hell

#

I didn't learn until I put the pencil down and tried to figure out easier ways to solve the same problems and why I struggled

novel sparrow
#

I have to agree with you 100%

remote mesa
#

It's completely stupid. You'll be so burnt out you won't have any energy left to learn or retain

novel sparrow
#

50-70 questions isn’t necessarily bad. Studying for exams over 100’s of questions that is bleak bleak bleak

remote mesa
#

It's that + everything else on top of it

#

In my case our lecturers barely could speak english

#

I got further teaching myself and being lazy

novel sparrow
#

What class are you taking

remote mesa
#

Being lazy can be good for retention sometimes actually

#

Right now I'm being gatekept by academic standards so I'm taking more algebra in a different program

#

This time we don't have a teacher or a book lmao

#

But I have the cheat codes already

novel sparrow
#

Yeah that sucks, web assign sucks. I am taking calculus. Homework isn’t bad, quizzes aren’t bad.

The exams fuck lol

#

The exams are like the only thing that matters it’s like 70% weighted

remote mesa
#

Some schools expect most of their students to fail higher math courses

novel sparrow
#

I’m in college btw

remote mesa
#

I'm starting to see why the US has such low scores now

novel sparrow
remote mesa
#

That's a damn good sheet

#

Well to be fair word problems are supposed to be the hardest ones to solve but some involve trickery or wordplay

remote mesa
novel sparrow
remote mesa
#

We are also using algorithms written by leaders of ancient cults

novel sparrow
digital mirage
#

why we took n -----> infinty ? fucntion is bounded b/w [a and b] does n-------> means infine partion ofr maximum accuracy ? or not then why n is approaching infinity ?

summer ruin
#

because you can't measure area under the curve with finite number of rectangles

#

as a consequence the width of each rectangle is reduced

whole nimbus
#

Does anyone have any worksheets they could send me about transformations of functions AP precalc?

hot holly
#

Can someone explain this form of the binomial theorem is (with the floor n/2 and n choose 2k). You can ignore the cosine and sine (problem was about finding a polynomial with roots of cos2kpi/n)

warped cipher
#

I've never seen binomial theorem in precalc

vernal pine
#

Aakarsh and Claire were just in math class together, but they have different destinations.
Aakarsh sets out at 1:30 PM, immediately after class, headed due north at 11 feet per second. Claire stays
behind for 15 minutes to ask the instructor a question, and then sets out due east at b feet per second. What
is the lowest number b can be that will make Aakarsh and Claire coincide?

#

Im having trouble figuring out how to find it

hushed sphinx
#

If they're going in different directions, then it sounds like no b will ever make them coincide ...

#

(Unless Aarkarsh contrinues straight ahead after he reaches the north pole and then moves south until he meets Claire who has gone the other way around the world).

jagged vine
#

can somebody walk me through this?

#

please

slim steppe
#

You have your x value (8) and your y value (3). So 3=Log base a of 8

#

So what is some value that you cube it to get 8

#

2

#

So your a is 2

#

So it will be y=log base 2 of x

jagged vine
#

ty that makes sense

viscid thistle
#

Does precalc help you with calc?

blazing hearth
viscid thistle
#

Purposefully makes it a difficult checkpoint for even advanced learners to diminish their mathematics confidence

viscid thistle
#

luckily I will only be taking 9 weeks of it

#

becuase my second semester is trig/precalc

#

i’m on alg 2 now

#

it was more satire but ok

#

👍

#

gl!!

carmine aurora
#

Can someone explain how it goes from 1+cos=4-4cos*
To 4cos*+cos-3=0

raw hill
obsidian monolithBOT
#

Civil Service Pigeon

carmine aurora
#

Thanks

dapper estuary
#

I don’t understand the second step

#

What does performing the inverse function mean?

summer ruin
#

logarithm and exponential function are inverse functions of each other

sullen jewel
#

please answer this general form to standard form

slate crane
sullen jewel
slate crane
slate crane
# sullen jewel ye

okay so you pretty much already have it in that form: mx+b=y
but y has a coefficient in front of it, so you divide by 8 on both sides (cause what you do to one side, you always have to do it it to the other)

slate crane
#

yes sir

#

@sullen jewel ^

sullen jewel
slate crane
slate crane
# slate crane yes, but some schools use Ax + By = constant

oh I totally didn’t see that it was an x squared, your answer is 100% right. just the formula for standard form is y=ax^2 + bx + c whereas the formula I supplied previous is for a linear line. yours is a parabola where a=1/8 (coefficient of x^2), b=0 (coefficient of x, since you don’t have an x variable), c= -2

vast quartz
#

me personally, i'd rather not start calc without knowing any trig or college alg concepts

#

ive been self studying a bit of precalc and it's only made me more confident

viscid thistle
#

I was joking, but even then personally my hs teaches trig concepts in alg 2

normal coral
#

is there any pretty notation denoting that f(x) is symmetric to the y-axis other than:
f(x) is symmetric to the y-axis

#

I doubt there is but just wondering

normal coral
#

I mean ofc there are gonna be some out there that don't but I'm pretty sure most do

dapper estuary
#

I don’t understand the second step

#

Please explain me how it got there and what performing an inverse function is

summer ruin
#

log and exponential are inverse functions of each other

drowsy cypress
#

@normal coral

Even Function - Symmetric about y-axis
f(-x) = f(x)

Odd Function - Symmetric about origin
f(-x) = -f(x)

lunar viper
normal coral
warped cipher
dapper estuary
#

Ye? What’s up

warped cipher
#

nah just wondering what the heck is remix next to your name

#

thats a new thing?

young sable
#

Guys

#

How do you do rational function word problems

solid pilot
#

Explicitly

sage lichen
#

Can anyone help me?

dapper estuary
warped cipher
fast kiln
#

how would you identify whether a function, for a given domain, is an increasing function or decereasing function, or neither? For this question, I found the first derivate but then I don't know how to determine the type of function

summer ruin
#

if the derivative is non-negative, then the function is non-decreasing

#

if it's non-positive then the function is non-increasing

warped cipher
#

<@&268886789983436800>

hollow hedge
#

Thanks

rain palm
#

my teacher didnt give the reasoning as to why a cubic is guaranteed

#

if anything that plotted out looks like a parabola to me

hushed sphinx
#

The strange thing is that the table gives the coordinates of five points, whereas the text claims there are only four ...

sage lichen
#

help anyone

#

||@Helpers||

small hatch
#

How do I find U1 in a geometric sequence if all I have if U7=24 and U15=384?

long hearth
#

Bro what even is dy/dx

icy star
solar olive
long hearth
native fulcrum
long hearth
#

thought i was onto something

normal coral
# long hearth Bro what even is dy/dx

if you are familiar with the notation of $\frac{\Delta y}{\Delta x}$, you can think of $\frac{dy}{dx}$ as an infinitesimally small change in y over an infinitesimally small change in x.

obsidian monolithBOT
#

saddayyy_

summer ruin
#

you can, but don't starebleak

normal coral
#

but be mindful that it isn’t exactly the same thing, it’s just an analogy that helped me learn the concept of a derivative

brazen canopy
#

Hey can someone help me out with this question

normal coral
summer ruin
#

even then the analogy doesn't even make sense since there's no such thing as infinitesimal change in classical analysis

pine geyser
# brazen canopy

First step is to find "b", you know that the first month is going to be:

ab^1=620

and the forth month:

ab^4=1083.

Now you should:
1.Divide these two equations in order to find b (ab^4/ab)
2. Now that you have b, put that in one of the equations, and you will find a
3.then for the answer obviously: ab^24 = ?

#

The numbers are really messed up

raven stone
sage lichen
sage lichen
raven stone
#

im not sure how useful id be LOL 😭

pine geyser
pine geyser
#

We got two points from the exponential function which one of them is (0,18) and the other one is (4,2):

When g(0) = 18 so:

ab^0=18

And we know that every number that has the power of zero would equal to one. So you can find out the value of "a".

Now we will use the second equation (4,2)
Now that you know the value of "a", you can easily find the value of "b" using g(4).

pine girder
#

did anyone answer the first question

#

@sage lichen

#

because I can hel

#

p

sage lichen
pine girder
#

@sage lichen

sage lichen
pine girder
#

alr

#

we have ab^x

#

for x=0, ab^x=18

#

so ab^0=18

#

a*b^0 is the same as ax1

#

so a=18

#

all clear so far?

#

alr I suppose it is

#

18*b^4=2

#

b^4=1/9

#

b=1/root3

#

so we have ab^x=18(1/rt3)^x, which is the same as 18(1/3)^x/2

sage lichen
#

mhm

#

pr8 it

pine girder
#

?

sage lichen
#

appreciate it (pr8 it)

pine girder
#

ok'

#

np

viscid thistle
#

hii

#

im new here

#

i need serious help

hushed sphinx
#

The way to get any help is to ask some questions and not flail around in all the channels. See #❓how-to-get-help.

raven stone
brazen canopy
#

Hey guys if anybody is in AP Precalc send me a dm we can help each other out yk

#

for future

lament anchor
#

Can anyone tell me what I did wrong?

quick plinth
#

or (1/2, 3/2)*

quick plinth
#

so for f(x) < 0, x is between 1/2 and 1, and 1 and 3/2. same as x is between 1/2 and 3/2

long hearth
delicate bolt
#

just started differntiation and i cant understand this chain rule man

#

i even tried yt vids and like i pretty much memorized it at this point but havent understood it

#

just having it memorized was working fine till i tried differntiating e^(x*ln(2)) and I couldnt

uncut blade
#

Have you seen 3 blue 1 brown's essence of calculus explanation?

delicate bolt
#

helped a lot but

#

still not completelty there

uncut blade
#

Ah fair, that one helped a lot for me

hushed sphinx
#

Chain rule is soundly #calculus, not pre. But it would be easier to get useful help if you can state your confusion with more specific words than "I don't understand".

delicate bolt
#

Hm

delicate bolt
#

gonna give it a try myself again tho

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YO WAIT I THINK I JUST GOT IT

patent turtle
#

number 4

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help pls

slim steppe
patent turtle
#

oh dw i solved it

slim steppe
#

Yeah, I know. I saw in the calc channel

patent turtle
#

i was jus confused with the definitiion

patent turtle
lunar viper
last pine
#

Guys, will there be eulers number on the test tomorrow

#

Also

#

If your trying to solve a exponential equation with (216^1/3)^5

calm fractal
#

anyone know why the 3 is a negative

#

nvm i know why

torpid oyster
digital mirage
#

then how is this coming ?

#

is cos(x+a)=sin(x-a)?

bitter compass
#

can someone explain to me where 4sqrt(U) du was obtained?

slim steppe
viscid thistle
#

alright

#

given an exponential function how would you find its equation? (it can have any transformations but not horizontal transformations)

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i mean like horizontal strech or shrink

haughty tapir
#

ello i wouldve just put the message in this channel but i didnt know it existed, heres my question

#help-35 message

marsh cloud
#

Fr

fleet drift
#

yo any way to visualise sin/cos/tan to make learning about it more intuitive?

wraith tiger
#

i feel so foolish how do i write the derivative of the inverse of function f

balmy orchid
#

why are people posting calc questions here

viscid thistle
warm oyster
#

i had to prove volume of sphere is equal to 4/3 pi r^3, i am getting 8/3 pi r^3

red knot
#

What do you want

#

A cookie?

warm oyster
#

huh?

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oops

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@red knot

hushed sphinx
warm oyster
#

,, \mathrm{V=\pi \int_0^{2R} {R^2 \cdot dR}}

obsidian monolithBOT
#

Yajatjamal

warm oyster
#

this is what im solving, i did a cylindrical element

analog flower
warm oyster
#

yea me too

#

this is what i tried to do

warm oyster
#

<@&286206848099549185>

warm oyster
#

wait

#

it should be

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,, \mathrm{V=\pi \int_0^{2R} {R^2 \cdot dr}}

obsidian monolithBOT
#

Yajatjamal

warm oyster
#

maybe something else

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,, \mathrm{V=\pi \int_0^{2R} {P^2 \cdot dr}}

obsidian monolithBOT
#

Yajatjamal

warm oyster
#

this one is right

warm oyster
#

(nvm got it)

vast quartz
#

I'm somewhat doubtful this is precalc

warm oyster
vast quartz
#

Idk there's just something about it

#

Could be the integral but idk it's at the tip of my tongue /s

hot holly
#

Lmao my AP calc class hasnt even taught this yet

hot holly
#

Can someone explain how they do this

analog osprey
#

can someone tell me why it isnt also associative

late basin
#

I've gotten this far but don't know how to rationalize it

prisma oriole
#

anybody know how to find the time that the ball is in the air?

vapid plaza
rotund crystal
#

Why do even functions bounce back even when they're below the x-intercept? Like doesn't any negative number when raised to an even power become positive

elfin matrix
#

$ln(2i\pi\times e^{2i\pi})=ln(2i\pi)+2i\pi$

obsidian monolithBOT
#

caffeine

elfin matrix
#

is this correct?

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$ln(2i\pi\times e^{2i\pi})=ln(2i\pi)+ln(e^{2i\pi})$

obsidian monolithBOT
#

caffeine

elfin matrix
#

going off the idea that the ln and e cancel in the last term of the equation

elfin matrix
pine geyser
fiery cobalt
prisma oriole
pine geyser
gaunt glen
#

:orz:

timber spindle
#

Has anyone here done calc 2?

past grotto
#

Hi...any study room?

green mulch
hot compass
#

Calculate the mobility of electrons in copper at a temperature of 0°C, if the specific thermal conductivity of copper at this temperature is 414.8 Wm-1K-1 and the concentration of electrons in copper is 8.427.1028 m-3. Start from the Wiedemann-Franz law.

Constants: e=1.602.10-19 C I k=1.38.10-23 J/K
help plz