#precalculus

1 messages · Page 47 of 1

jovial coral
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But for the y we have to take the derivative of y with the standard notion that we are derivating with x

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I'm not really good at teaching I'm sorry if you don't understand

stiff depot
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Instead of checking the tangent line at x you do it at the y

proven night
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Hello guys

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I always manage to fail when it comes to trig equations with restricted range of solutions, for example cos(x) = 0 but x € [-pi;pi]

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Am i right if i just get the general solution (pi/2 + pi*k) and then i just substitute k with random integers (for example, -1, 0, 1 etc)?

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And then i just check whether the solution is within given range

summer ruin
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yes

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but it's obvious from the trig circle which x solve this particular equation

foggy valley
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I recently just got in pre calculus class and was talking about circles. I've been stuck for 2 hours in this assignment I have which is

"Find the equation of the circle that passing through p1 (-3,6), p2 (-5,2), and p3 (3,-6). (General equation)" I watched a tutorial video with each having different methods, I had done the equations 1,2,3 and so on. Doing the elimination method. But I just don't seem to know if I'm doing it correctly

P.s I even used some ai like chatgpt and IT MADE MY UNDERSTANDING WORSE

uncut mulch
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don't use gpt, show what you did

frank spindle
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Dont use chatgpt with that stuff

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It spits out nonsense 99% of the time regarding math

foggy valley
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So I followed this video tutorial BUT IDK I'M NOT SURE IF I'M DOING IT RIGHT

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I did the equations and subtract the equation 1-2 which you'll get the equation 4 and 1-3 which would be your equation 5, after that you'll subtract it again

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I DONT KNOW

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"Find the equation of the circle that passing through p1 (-3,6), p2 (-5,2), and p3 (3,-6). (General equation)"

frank spindle
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The equation of a circle is (x-h)^2 + (y-k)^2 = r^2

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Where (h,k) is the center

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Thats the general equation if i recalll

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You can easily solve for r with the information given

uncut mulch
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its more or less the same, you end up with a system of 3 equations

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one thing that stands out is the notation issues

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when squaring stuff like -3 and -5
you MUST have () around them

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${\red{(\black{-3})}}^2$

foggy valley
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I don't know if I'm even doing it right anymore:( I'm lost

obsidian monolithBOT
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ℝαμΩℕωⅤ

uncut mulch
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can't check every single detail
but you seemed to have reached a system of two equations
try solving that to get the values of D and E

foggy valley
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I don't even know, like can I get the value of D or E in this equation "(16 + 2D + 4E) - (-6D + 12E)"

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What did I do wrong T-T

uncut mulch
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if you want to approach it with elimination,
you'd want the magnitudes of one of the coefficients to be the same before you add/subtract, depending on personal preference

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which can be achieved by multipling one or both equations by an appropriate value

foggy valley
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If I want to eliminate D for example

I'll multiply

16 + 2D + 4E to 6

while I'll multiply -6D + 12E to 2?

uncut mulch
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you can be more efficient considering lcms

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considering that the lcm of 2 and 6 is 6,
its sufficient to multiply that first equation by 3 or -3

foggy valley
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IDK IF IM DOING IT RIGHT

uncut mulch
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show your attempt?

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this is going on in two places, choose one,
here or #help-32

uncut mulch
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<@&268886789983436800> political shitpost

modest vine
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At least i think that should work idk

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Yep that works

daring tapir
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Whats a fucking GPT Im interested bleakkekw

winter comet
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i don't think we wanna know

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💀

daring tapir
daring tapir
winter comet
muted sun
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Hello can anyone help me understand this?

willow skiff
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If you change the angle by 180 degrees, the point will become directly opposite and thus have the same slope

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Same for 360 deg ofc

muted sun
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I appareciate

trim isle
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hello,can anyone help me? I don't fully understand what I'm doing

somber void
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that's a cool problem i reckon

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So ok

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1x - (-1)y = -3
and
7x - (1)y = 7

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We need to do 2 things:

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  1. We need to find the intersection point, because bisector has to pass through that
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  1. We need to find the slope of the bisector
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For 1 we can just solve the system of equations to get

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2 is cool i think

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because

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1x - (-1)y means that for every 1 unit to the right the line goes 1 unit down.
7x - 1y means that for every 1 unit to the right it goes 7 units up

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it would be nice if there was some system that represents rotation with pairs of numbers...

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oh wait

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it's the complex numbers

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so
-1 + i and 1 + 7i represent the angles

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we can multiply them together to get double the rotation
(-1 + i)(1 + 7i) = -1 -7i +i - 7 = -8 - 6i

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but the problem is that we actually need their average

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which means that we need to find the square root of that somehow

hasty lily
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Wouldn’t basic trig suffice

somber void
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i mean yeah but that's boring

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(a+bi)² = (a²-b²) + (2ab)i
(a+b)(a-b) = -8
2ab = -6
a = 1
b = -3
works

hasty lily
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Complex numbers are just trigs

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Actually they’re based on e^x and Taylor series

somber void
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1-3i

hasty lily
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What’s with my enter key today

somber void
modest vine
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My god I just wanted the image

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But the trig part is from that right

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Oh nevermind it's just vectors 😭

somber void
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on one hand we got lucky that the sqrt is nice

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on the other hand we got unlucky that we had to do this by hand

willow skiff
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that is unfortunately the wrong line: you have bisected the obtuse angle

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luckily the fix for this is to make one of the sides negative

the correct version of the distance to a line formula has absolute value signs: for example, if we have |x| = |y| and x = y doesn't hold, we must thus have x = -y

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then it's literally just:

trim isle
willow skiff
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I have another approach using the angle bisector theorem actually:
the point (0, -7) lies on the blue line and the point (4, -7) lies on the red line, and their intersection is at (0.5, -3.5)

so using the angle bisector theorem
our bisector must pass through $\left(4 \cdot \frac{ \sqrt{0.5^2+3.5^2} }{\sqrt{0.5^2+3.5^2} + \sqrt{3.5^2+3.5^2} }, -7 \right)$

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wait that's not right, I checked on Desmos

willow skiff
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that explains everything

trim isle
willow skiff
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okay that makes more sense

trim isle
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yeah

obsidian monolithBOT
willow skiff
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simplifies down to (5/3, -7)

trim isle
# willow skiff

question: how to know if I've bisected the obtuse angle or the acute angle.. ( teacher hasn't taught us yet )

willow skiff
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from slope = -a/b

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so that means the bisector has to have negative slope, if you make a sketch

willow skiff
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so that means that if you choose the positive sign on both sides of the equation, that's the wrong bisector

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you need to make one of the sides negative

trim isle
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hmmmmm, ok, i can comprehend what you just said. I'll do the rest, Thank you c:

willow skiff
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if there's a better method it's probably more slick

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but you need to figure out which of the angles is acute which depends on the two lines so it can't be that short I think

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nw

timid belfry
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Can I get some help with this one pls... it's expaded to standard equation of a circle. I used the method my teacher used for the later question but my classmates all have different answers on no.4. I genuinely don't know what I'm doing...

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I've been up the entire night trying to figure out which part I got wrong...

still tendon
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Hi im not rlly sure where to ask this but i just started pre calc (only half way through functions unit) and am kinda annoyed there r still word problems theyre actually the bane of my existence. I was wondering if they get easier in the future with calc n uni math

winter comet
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how hard your problems are really depends on your teacher tho

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it might get "easier", might get "harder"

uncut mulch
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when you are familiar with the terminology, there shouldn't be too much of an issue setting up the equations
whether you have difficulty solving those is a separate issue

modest vine
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You made an error when factorising

timid belfry
still tendon
oak bluff
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Uh Im kind of confused because it looks like none of the options are correct

cyan berry
oak bluff
cyan berry
oak bluff
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but thanks anyway

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yeah

cyan berry
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All goodie then

oak bluff
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(2^2)^t/2

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2^t

cyan berry
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Yeah thats basically it : )

oak bluff
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: D

unreal dawn
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you can just check both lines and see which does have the positive slope as someone lse said

brittle geode
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i did tan^-1(9)= 83.6

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and then rounded to 83.7

winter comet
brittle geode
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oh

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so 180-83.6

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= 96.3 ?

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when i added 180 to 83.6 i got (263.7)

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which i discard because is over 180 degrees

winter comet
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nah wait what

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there aren't any other angles what am i on

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i have no idea why thats not correct 💀

brittle geode
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okay

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thank for your time

winter comet
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have you tried putting in 83.6 just in case they round wrong?

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or u only have so many tries 💀

brittle geode
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i have 2 tries

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i used one

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so its my last chance

winter comet
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yeah ok so you gotta be sure 💀

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uhh

winter comet
brittle geode
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i emailed her on friday but no response

winter comet
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dang

brittle geode
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I checked multiple times

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and notice that for that specific problem i had to put the degree sign

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which didnt really make sense because the answer was telling me to put in degrees already

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but thank you for your time and patience!

winter comet
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how do you even put a degree symbol 💀

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is part of the program?

brittle geode
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no 💀

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LOL

winter comet
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💀

nocturne cave
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I found someone saying that it was possible to solve a linear system using matrices, and he showed this equation. Can someone tell me what the name of this method is and if it really works? I would like to learn more about it.

rx + sy = t
summer ruin
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the inverse matrix

hushed sphinx
flat shuttle
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Would a quadratic model have small residuals and the residuals plot show no pattern?

brittle geode
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i just wanted to double check this problem

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my answer is -sqrt3

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is that right?

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🙂

desert void
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yep

modest vine
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Uh let's say there's a type of sequence that is defined by two seed values
F(1) and F(2) and F(n+1)=F(n)+F(n-1) basically the fibonnaci sequence but for any two seed values

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How can I determine if two pairs of numbers belong to the same sequence

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Like for example for the normal fibonacci sequence both 2,3 and 1,1 belong to the same sequence

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I could just continue the sequence but that'd take a bit long in some cases

somber void
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If F is increasing you can do a binary search

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You can also maybe do mod, and see if it appears in the same sequence

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there's also F(1)f(n) + F(2)f(n+1) = F(n+2)
where f(1) = f(2) = 1 and f(n+2) = f(n+1) + f(n), and F is your sequence

somber void
normal shadow
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how can i use a calculator to get coordinates on a unit circle

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i have memorized the method to remember radians and degrees on the unit circle

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but i dont know how to figure out the coordinates / memorize them using some kind of rule

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so how can i get them with a calculator

placid bone
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but you know that the x coordinate on a unit circle is cosine of the angle, and the y coordinate on a unit circle is sin of the angle

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so if you have the radians/degrees memorized, you can find the coordinates pretty easily off of that principle

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but it's honestly 10x better to just memorize the coordinates, makes trig problems so much smoother

somber void
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you want 1/6 of a turn? that's τ/6 radians and 360/6 degrees. Put that into calculator and you have your x and y. Don't have calculator? Realize that 60° is the angle inside the equilateral triangle. Drop height and see that cos(60°) = 1/2. Use pythagoras to get sin(60°) = sqrt(1² - (1/2)²) = sqrt(3/4) = sqrt(3)/2 that's something like 0.85 i think

normal shadow
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when solving for inverse values of trigonometric functions, do I have to graph them and/or look at the unit circle to find their values, or is there some kind of equation that can be used

river drift
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not really any way to find values of trig or inverse trig functions other than known values

lyric sleet
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anyone help me with this?
300.
A toroid is a rotational body where a plane figure rotates around a straight line that does not intersect the plane figure. For example, the holed wooden ball from the previous problem is a toroid. If the rotating plane figure is a circle, it forms a torus, which is a special case of a toroid.

a) Calculate the volume of a bicycle's inner tube when its inner radius is 25.0 cm and the outer radius is 29.0 cm. The cross-section of the inner tube is a circle.

b) Calculate the volume and mass of a gold ring when the cross-section of the ring is a semicircle, the inner diameter is 18.0 mm and the outer diameter is 19.5 mm. The density of the gold alloy used in the ring is 17.3 kg/dm³.

I'm currently doing the **b) **, and been stuck getting answers like 49.96 or 52 when I should get 51.7

The second picture is is the a), because the two are similar so I think you solve them quite the with the same technique.

The radius of the inner circle is 9 (18/2) and outer circle 9,75 (19,5/2). So the width of the ring should be 0.75. Because you can think it as half of a round ring, it should 9 should be the distance from the origon to the center of the ring (if it was whole).
x^2-y^2=r^2 so then I think you could just (x-9)^-y^2=0.75^2 so x=9+-sqrt(0,75^2-y^2).
Then you plug it in the integral from -0,75 to 0,75 and put (pi/2)*f(y)^2=(pi/2)(9+-sqrt(0,75^2-y^2))^2 as the function. There then comes the problem as I get the answer 49,964.

uncut kestrel
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Find the concavity of the functions in diff intervals $f(x)=\frac{x-2}{(x^2-x+1)^2}$

obsidian monolithBOT
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TᖇᗩᑎᔕᑭᗩᖇEᑎT ᔕᕼᗩᗪOᗯ

willow skiff
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like this, check the first derivativ

uncut kestrel
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Find the concavity of the functions in diff intervals $f(x)=\frac{x-2}{(x^2-x+1)^2}$

obsidian monolithBOT
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TᖇᗩᑎᔕᑭᗩᖇEᑎT ᔕᕼᗩᗪOᗯ

uncut kestrel
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I got the second derivative and got

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And I got $x =\frac{4 \pm \sqrt{6}}{2}$ and $x=0$

obsidian monolithBOT
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TᖇᗩᑎᔕᑭᗩᖇEᑎT ᔕᕼᗩᗪOᗯ

uncut kestrel
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I represented them on the number line

willow skiff
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,w second derivative of (x - 2)/(x^2 - x + 1)^2 = 0

uncut kestrel
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Isn't $\left(\frac{4 + \sqrt{6}}{2} ,+\infty\right) \approx \left(3.2 ,+\infty\right)$ ?

obsidian monolithBOT
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TᖇᗩᑎᔕᑭᗩᖇEᑎT ᔕᕼᗩᗪOᗯ

willow skiff
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cool that's correct (there's also 2 + sqrt(3/2) which got cut out)

uncut kestrel
willow skiff
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cause 2 + sqrt(6/4) = 2 + sqrt(3/2)

uncut kestrel
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But when I put 4 it becomes negative

willow skiff
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wait

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oh right you are finding concavity, continue

uncut kestrel
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And 4 is literally under tat interval I mentioned

willow skiff
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f''(4) is still positive

uncut kestrel
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I got $x(2x^2-8x-5) = 0$

obsidian monolithBOT
#

TᖇᗩᑎᔕᑭᗩᖇEᑎT ᔕᕼᗩᗪOᗯ

uncut kestrel
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I'm equating the second derivative to zero

willow skiff
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6x(2x^2 - 8x + 5) = 0

uncut kestrel
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Not -5
My brain

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I hate quotient rule 💀

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Anyways tysm 🥹😭@willow skiff

willow skiff
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you can literally use Wolfram Alpha and Desmos/GeoGebra to check yourself

uncut kestrel
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30 mins wasted 🤣

willow skiff
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next time

uncut kestrel
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I'll do some other problems now
I'll be back if I need help ✨💫

mystic sluice
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I’m looking for question a

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How do I find the asymptotes of this function and there is 2 horizontal

willow skiff
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as x tends to -infinity, you get -x^3 / (-x^3) = 1

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as x tends to infinity, you get x^3 / (-x^3) = -1

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because $|x| = -x$ if $x < 0$

obsidian monolithBOT
willow skiff
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|-5| = -(-5) = 5 for example

young gust
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Hello

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Precalculus is awesome XD

keen fox
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@young gust hey which uni do u study at?

mystic sluice
ember hemlock
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Hey, anyone from India??

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I need help with the whole syllabus 💀

modest vine
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I'm making a graphing calculator

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How should I handle asymptotes

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I use lines to connect points

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So the asymptotes kinda have this vertical line connecting the two ends

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How can I detect asymptotes

daring tapir
modest vine
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Anyway im essentially just putting pixels

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So it shouldn't really matter that much

daring tapir
modest vine
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Never mind then

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The people there told me to ask a math server😭

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That's why I came here

daring tapir
modest vine
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No I don't need it in c++ I just need a general algorithm

daring tapir
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Cuz writing the algorithm for finding the derivative is gonna be too lengthy and im pretty sure there is already some library for that

modest vine
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Whatever ig I'll just search for libs 😭

daring tapir
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Hmmm

viscid thistle
modest vine
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Recursive refferals 😭

viscid thistle
daring tapir
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But not recommended

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I mean he could use the openai api

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Which is doable but will probably be more expensive than coding it himself

winter comet
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how to solve for t with just a calculator?

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😐

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oh they probably want you to graph it ._.

jagged nova
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I had a question about partial fraction decomposition. If you are trying to split say 3/(x^2+1)(x-2), would it be impossible to split this fraction if you are limited to the real numbers? My reasoning is that typically to solve for the numerator of either fraction you need to set each polynomial equal to zero, but x^2+1 has no real solutions.

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Sorry if this isn’t the right place for this question I didn’t know quite where to put it

summer ruin
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x-2 has real roots, so it is possible

viscid thistle
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For some time

daring tapir
winter comet
viscid thistle
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Yea

daring tapir
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Well i guess some is not enuff for a calculator

viscid thistle
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I'll try

jagged nova
winter comet
#

then you can create a system of equations to solve

summer ruin
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,w partial fractions 3/((x^2+1)(x-2))

obsidian monolithBOT
jagged nova
#

Interesting, thank you thank you. I am curious then if you can ever not separate the fraction, and if so what the necessary and sufficient conditions are for that to be the case.

dapper rune
#

Can somebody tell me how to prove that there are inf prime numbers?

jagged nova
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For the sake of contradiction assume there are finitely many prime numbers, say n of them. Then consider the product of all of those prime numbers and add one to that:

$$p_1 p_2 p_3…p_n +1$$

Now you should be able to reach a contradiction from here. Does that make sense?

obsidian monolithBOT
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Squirtle Squad Gang Affliate #1

jagged nova
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There are two cases, one where $$p_1 p_2…p_n +1$$ is prime, and one where it is not prime

obsidian monolithBOT
#

Squirtle Squad Gang Affliate #1

full mirage
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when finding how many complex zeros a polynomial can have, can you just graph the equation, count the zeros normally, then mulitply the number of zeros by 2?

somber void
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counterexample:
x² + x + 1

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has 2 complex zeroes, but 0 real ones

river drift
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the fundamental theorem of algebra says that the number of complex (incl. real) zeros (counting multiplicity) = the degree of the polynomial

uncut mulch
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the number of effort points needed to ping <@&268886789983436800>
(trivial addition troll)

heavy merlin
#

not gonna lie I'm just starting pre calc in school and I'm probably gonna need some help later on but hopefully I don't.

turbid breach
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(𝑥 + 1)² + (𝑦 + 1)² = √26 how do I get the radius of the circle if it's already in a radical? Do I get the fourth root?

safe basin
zinc compass
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On Sept 9th I'll have to take an exam about differential calculus, subjects are limits, derivatives, numeric successions, functions and so on.
Would you say Khan Academy is a good resource to learn these things?

I'm currently learning trig on Khan Academy, since I lack trig and as I understand it's definitely something to learn before heading to more advanced calculus concepts

uncut mulch
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its a good place to start

turbid breach
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Aren't all of these circles?

summer ruin
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no

uncut mulch
#

how are you reaching that conclusion?

turbid breach
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All of these are A = B. A being the coefficient of x2 and B being the coefficient of y2

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I saw it from some video

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Is it wrong?

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Teacher hasn't really taught us anything, just told us to answer this

uncut mulch
#

its flawed

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consider
x^2 + y^2 = -100
would you consider this to be an equation of a circle?

hushed sphinx
#

That teacher should be forced to take their own horribly mistypeset exam...

uncut mulch
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also ^

hushed sphinx
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^ indeed.

turbid breach
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No

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Ok I think(?) I get it

uncut mulch
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so here, you'd want to do something like express these equations in standard form

turbid breach
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Ah, thank you so much

hushed sphinx
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We can shortcut (6) and (7), because once we find even one point where the LHS is <= 0, the equation must make a circle somewhere

narrow briar
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Hi! One question: can I use Lambert’s W function for solving this equation? 2^x = -x^2 -3x +44

hushed sphinx
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Looks unlikely.

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The typical way to check is to type the equation into Wolfram Alpha and see wether it produces an expression that involves W.

winter comet
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v and w and v+w are referring directly to vectors, not magnitudes, right?

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💀

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i feel kinda stupid i thought they were talking about magnitudes and i was like erm no 🤓

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yea i think its just the vectors themselves 💀

modest vine
#

Classic tail to tip vector addition

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Physics class ahh addition

winter comet
winter comet
modest vine
#

Which is totally goated

winter comet
modest vine
acoustic spoke
#

Can someone help me out! I don't understand how to do arcsine, arccostine, and arctangent problems like this without a calc

willow skiff
#

show the options of the question

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but to get the principal angle, you just keep adding pi until you are more than 0, cause the period of tan is pi

acoustic spoke
willow skiff
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you can figure it out though without one

acoustic spoke
willow skiff
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from the options

willow skiff
#

because cos x passes through (0, 1) and (pi, -1)

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so when you take the inverse, those points are now (1, 0) and (-1, pi)

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we have chosen those two points cause that's the largest domain where cos x is one to one

[-pi, 0] also works as a domain for the inverse, but that's a bit weird to have only negative numbers

acoustic spoke
spice vault
#

Yo how to do I solve

( 16x² + 96 + 2,304) + (16y² - 40y +400) =315

Idk how to solve cause the x has a number

Ps. Pls tag me if u know the answer

willow skiff
#

what are the conditions on x, y?

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that's weird

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,w (16x² + 96 + 2304) + (16y² - 40y +400) =315

obsidian monolithBOT
willow skiff
#

you see that -4x^2 - 615 < 0

modest vine
#

I'm pretty sure this is just a circle

willow skiff
#

nope discriminant still negative

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,calc 96^2 - 16 * 2304

obsidian monolithBOT
#

Result:

-27648
willow skiff
modest vine
#

Yea the radius has a negative sqrt

trim isle
#

hello! can someone help me understand this?

elfin cargo
#

Do you know that the intersection of angle bisectors of a triangle is an incenter?

elfin cargo
#

The only method I can think of is to find the equation of 3 angle bisectors and then find their intersection which is the center of the circle inscribed

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Actually we only need to find 2 angle bisectors

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Wait we still need 3 to locate incenter exactly trollge

#

Even though, this method can still lead to correct answer but it is quite long so I don't know if anyone has a better method

willow skiff
#

x + 2y - 5 = 0 and 2x - y - 10 = 0 are perpendicular

#

from the above diagram we first solve x + 2y - 5 = 0 and 2x - y - 10 = 0 to get (5, 0)

#

then solve the other two equations similarly: the sides are 3sqrt5, 4sqrt5, 5sqrt5

#

so r = sqrt5

willow skiff
# willow skiff

now note the square in the diagram: the vector (-1, -2) is perpendicular to the line x + 2y - 5 = 0 and the vector (-2, 1) is perpendicular to 2x - y - 10 = 0

both vectors already have length sqrt(5), which matches the radius

#

so the centre is just (5, 0) + (-1, -2) + (-2, 1) = (2, -1)

elfin cargo
somber void
#

there's a way to solve this that uses stupid amounts of linear algebra (use cramer's to solve for vertices, cross product to solve for sines of angles (or you can just find side lengths, that's easier), then use barycentric coordinates to solve for incenter)

raw hill
#

Angle bisector theorem + partioning a line segment moment:

brittle geode
#

hi, could someone help me with this ?

pulsar oxide
#

This isn't a function right?

uncut mulch
#

what's your reasoning

sharp yarrow
#

Each value on the horizontal axis (independent variable) corresponds with only one value in the vertical axis (dependant variable) right?

mellow sorrel
#

you know why I dont like cos and sin and stuff like that

#

because I have to use calculators for them and it is depressing to not be able to calculate them

chrome ether
#

not everything is a nice rational value

#

best get used to that now rather than later

arctic dagger
arctic dagger
arctic dagger
#

Because a vertical line only intersects the function once for every point on the function

pulsar oxide
#

What about these points though?

arctic dagger
#

It's like, imagine a vertical line intersecting those filled and empty circles, and x=a on that vertical line. The function must only have one value f(a) on x=a, and that value is the filled dark circle. The empty one is like open ended, it approaches a but the true value at a is the dark circle

#

And pls don't confuse a and f(a). a is the value on x-axis, f(a) is the value on y-axis

pulsar oxide
#

OJHHHH

#

My teacher didn't really explain that

#

Thank you so much

arctic dagger
#

Damn. Your teacher should. Or maybe you can ask ur teacher when something is confusing

#

But also sometimes it's hard to put smth in words things that u don't even know about

pulsar oxide
#

Yeah

#

Also

#

We're in online class

#

And there's no way to contact the teacher

#

So 😭

arctic dagger
#

I see

pulsar oxide
#

Thanks for the help!

arctic dagger
#

Yw

pulsar oxide
#

I treat this server more like my teacher than my actual one

lunar hemlock
# pulsar oxide

I think circle with no dark is means a value in under it is not included

#

And circle with dark us where a value ends like 5 > x, dark circle goes forever

#

You can just write it as arrow

little wigeon
#

Anyone able to VC

#

Real fast to explain a problem to me

#

Good karma awaits you

#

Or just DM

cyan canopy
#

I need a little help

willow skiff
#

Desmos and GeoGebra can actually do q8 for you

#

just type in {0 < x} for example

#

for the domain restrictions

cyan canopy
#

oh

#

But is this right?

willow skiff
#

8a is correct

cyan canopy
#

9?

#

How it’s not completely to scale tho

willow skiff
#

wait

#

sorry brainfart

cyan canopy
#

All good

willow skiff
cyan canopy
#

What about the characteristics

willow skiff
#

just state what you observe

cyan canopy
#

Like is there a VA for 8a?

#

but 0 has an end point

willow skiff
#

so there are asymptotes for 8 at x = 0 and y = 0, for x < 0 only

willow skiff
cyan canopy
#

9 is easy

willow skiff
#

that the graph is decreasing for x < 0 but increasing for x >= 0 etc

#

yeah you get the idea

cyan canopy
#

Ok thanks man

willow skiff
#

or you can make the slope at x = 7 increasing, that also works

cyan canopy
#

thanks you so much

willow skiff
#

np

#

it's testing your attention to detail

cyan canopy
#

Thanks again

native smelt
#

i need help

arctic dagger
native smelt
#

what formula am i gonna use?

arctic dagger
slender vault
#

Wooo

#

Lol

viscid thistle
#

The one that goes like (x-a)^2-(y-b)^2

little wigeon
#

Looking for a pre calc tutor to help me review for final. Willing to pay hourly rate

#

Please contact ASAP

pulsar oxide
#

How should I go about substituting this?

#

Specifically the f(x+h)

#

I don't know where to put the +h

simple tundra
#

f(something) is a function that has an input of (something) and an output of 3(something) - 1

#

So whatever that something is, whether x or x+h, you just put it where the (something) should go

pulsar oxide
#

So would 3(x+h) - 1 be correct?

#

Also, what does it mean by "each replacement value of x"?

crude solstice
#

for f(x) though it is obvious

pulsar oxide
#

Okay, I get it now

#

Thank youuuu

#

Can I do anything more with b?

river drift
#

you can multiply numerator and denominator by the conjugate

tardy ridge
#

I'm doing precalc this year, any tips?

arctic dagger
#

And i think that equation comes from the distance from the center (h, k) to every point in the circle. So it's basically a distance formula. As all conic sections are, i think

steel dew
#

how do i graph 86

willow skiff
#

so for x, you take off the whole number part, and so your range is 0 <= f(x) < 1

#

and there's a repeating pattern every 1 unit

echo verge
arctic dagger
# echo verge

Graph crosses x axis: odd roots
Graph touches x axis but doesn't cross: even roots

#

And mind the sign

twilit ridge
#

i need help with conic sections 😭 i don’t understand how standard and general form works

willow skiff
arctic dagger
#

(h, k)

#

No that's only for circle

willow skiff
twilit ridge
#

how can you find radius though in this problem

willow skiff
#

for example

willow skiff
twilit ridge
willow skiff
#

x^2 + y^2 = 2^2, radius is 2

twilit ridge
#

ohhhh

willow skiff
#

the full form is $(x - h)^2 + (y - k)^2 = r^2$, so you have $h = k = 0$ and the origin is the centre

obsidian monolithBOT
willow skiff
#

long story short, it's minus h, minus k
because x - 2 makes the graph go right by 2 units
(x - 2)^2 makes the parabola go right by 2 units, so it's the exact same with the circle

twilit ridge
#

ohh okay ,, thanks

twilit ridge
willow skiff
#

the general form of any conic is $Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0$

obsidian monolithBOT
spice vault
#

Idk how to solve, I need help

willow skiff
#

where the two bisectors meet is the centre

spice vault
#

Bro ngl, I'm very slow at math

willow skiff
#

no worries

spice vault
willow skiff
# spice vault So how? Could u pls give me an explanation can't really understand on how to sol...
  1. find the gradients AB and BC: $m = \frac{y_2 - y_1}{x_2 - x_1}$

  2. take the negative reciprocal, -1/over, the gradients AB and BC: those are the slopes of the perpendicular bisectors

  3. find the midpoints of AB and BC: the midpoint of (a, b) and (c, d) is ((a + c)/2, (b + d)/2)

  4. y = mx + c for both lines, where m are the gradients in step 2: sub in the x- and y-values of the midpoint to obtain c for both lines

  5. solve both lines simultaneously: either elimination or substitution works
    now you have the centre

  6. use Pythagoras to get the radius squared: with point C for example, $r^2 = (7 - p)^2 + (2, q)^2$ if (p, q) is the centre

  7. now you can write (x - p)^2 + (y - q)^2 = r^2

obsidian monolithBOT
#

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

spice vault
small shard
#

@little wigeon i got some messages to you

fiery crest
#

Im starting college and id like to get to calculus but I have no clue where to start. I've never completed a full math course before but I did ok in the parts I tried. Should I go straight for precalc or is it too far of a jump from not understanding algebra 2?

warped wharf
#

Can anyone help me with conic sections

pseudo osprey
fiery crest
pseudo osprey
#

At the end of the day, your success in these classes is dependent on how much time you take to understand each concept as it is given. Math may seem an insurmountable obelisk currently, but with enough concerted time and effort, that once-obelisk will morph and change, revealing layers of simplicity that make up the most complicated equations.

#

You too, can see math as others do—just as they once saw math the same way you do currently.

#

You can be successful.

fiery crest
#

Yeah I think I can do ok I just constantly changed schools so I never was able to learn anything

#

I don't really wanna have to redo a class

#

Especially cause I had no clue what was going on in algebra 2

pseudo osprey
#

It’ll suck but if you really think it’s the best thing to do for your understanding, you should.

pseudo osprey
fiery crest
#

I'm not sure if I should go farther back than algebra 2 cause I missed the last half of algebra 1. I did really good in the first half

pseudo osprey
pseudo osprey
#

Math is extremely rewarding and challenging—however, I’m sure you’ll find your peace with it eventually.

cedar drift
#

for precalc do i round this to 0

sinful halo
#

generally, you should leave it in scientific notation and round to 3 decimal places

gentle totem
#

Looks like just a floating point error

real briar
#

should i learn algebra 2 before precalc

cedar drift
#

yes

uncut mulch
#

its more or less the same

warped wharf
#

Here a quick question 1^x=2 solve x is a complex number

drowsy swan
#

Anyone know quickly what my teacher means by this

somber void
fading monolith
#

Also that is not precalculus

winter comet
dreamy pike
#

can someone explain this? i got it right from guessing the second answer but why is the identity suddenly (-180-theta)

summer ruin
#

a typo

viscid thistle
#

Calculus seems pretty hard

#

A lot of people says it is

#

Is this really the case?

boreal remnant
#

nah

winter comet
boreal remnant
#

maybe unintuitive at first

winter comet
#

of course it depends on how hard the teacher makes it

#

but like the core concepts are pretty easy

winter comet
viscid thistle
winter comet
viscid thistle
#

My older friends struggle

winter comet
#

it's kind of overrated imo lol

viscid thistle
#

I just rlly want to get it

winter comet
viscid thistle
#

Would you recommend prelearning

#

Calculus

winter comet
#

definitely

viscid thistle
#

Okay

#

Thank you

boreal remnant
winter comet
#

as long as you put in the work you should do fine

viscid thistle
#

I haven’t been taught it yet in school

viscid thistle
storm lodge
#

holy hell

#

crab

viscid thistle
#

SHH

#

I’m trying okay

winter comet
#

wait its a crab :O

viscid thistle
#

Bubo

boreal remnant
#

why tf yall talking to eachother in 5 different channels 😭

winter comet
#

a talking crab

boreal remnant
#

just chose 1

storm lodge
viscid thistle
boreal remnant
#

lmfao

winter comet
viscid thistle
#

No im not

boreal remnant
#

give ppl help in one of the help channels

viscid thistle
viscid thistle
winter comet
viscid thistle
#

Evidently so

boreal remnant
#

just pretend like you know what you're talking about

#

they'll listen

#

💀

viscid thistle
#

But thanks for the calculus help guys that I actually needed

winter comet
#

😂

winter comet
storm lodge
#

i dont have time to have an hour long conversation

boreal remnant
viscid thistle
winter comet
#

most days

storm lodge
#

doesnt matter

#

bc at the end of the day

#

its night

boreal remnant
#

i mean somedays just dont sleep and then u dont wake up so

winter comet
#

usually

viscid thistle
boreal remnant
winter comet
boreal remnant
viscid thistle
boreal remnant
#

discussy 😋

viscid thistle
#

Mhm

winter comet
viscid thistle
#

crab is not a food pls

#

It’s been wrongfully labelled as one

winter comet
boreal remnant
#

@viscid thistle

hushed sphinx
#

Kindly stop the random shitposting here.

storm lodge
viscid thistle
#

My bad tropo

boreal remnant
viscid thistle
fossil cypress
#

hi

#

i need hlep

winter comet
fossil cypress
#

like

viscid thistle
#

bro i dont remember anything about conics 💀

#

lemme search it up

winter comet
#

c = sqrt(a^2 - b^2) is for ellipse i believe

#

lol

viscid thistle
#

yeah and the -8 in the x term means its shifted to the right by 8

winter comet
#

yea

viscid thistle
#

@fossil cypress

fossil cypress
#

o

winter comet
#

we're just doing the problem for him 😂

viscid thistle
#

lmao

fossil cypress
#

wait

winter comet
fossil cypress
#

so

#

yes you divide the thing

#

by 2

#

hm

winter comet
fossil cypress
#

um nvm

viscid thistle
#

the fact that its shifted to the right means you find the vertices as if it wernt and then just add 8 to the x values of what you got

proven night
#

Hi

#

If i am quite good at precalculus (i need to get better only at logarithmic and trig equations), and i already know about derivatives, can find extrema of function, have basic understanding of continuity, limits, but i cannot solve harder limits, like i know how they work, but i didnt master solving them, so with this knowledge, can i start learning integrals?

proven night
timber blade
proven night
#

Okay

lime lotus
#

How do you put this in standard form:

#

In like this

#

When I tried to manipulate

#

this happens

summer ruin
#

what happens

modest vine
#

I guess we'll never know

lime lotus
lime lotus
modest vine
#

140y^2/35=(y^2)/(35/140)

summer ruin
#

and replace $y = \hat{x}, x = \hat{y}$

obsidian monolithBOT
#

Transparent Elemental

lime lotus
modest vine
#

Divide by 140 on both numerator and denominator

odd agate
lime lotus
#

on both sides

summer ruin
#

140/35 = 1/(35/140)

lime lotus
#

So this is the standard form?

odd agate
odd agate
lime lotus
#

Thanks!

willow skiff
#

conics are beautiful

viscid thistle
willow skiff
winter comet
willow skiff
#

actually the correct statement is quadratic forms are beautiful

#

but studying them is hell

viscid thistle
#

reading this

viscid thistle
#

wtf

lime lotus
#

how do you put this in equation

#

The product of the distances of P(x,y) from the coordinate axes is 5.

winter comet
hushed sphinx
willow skiff
lime lotus
#

is this right?

winter comet
#

not quite

#

the distance from P(x,y) to the x axis is that, but its not equal to 5

odd agate
#

How do I write subscripts?

winter comet
#

i do like a_n

odd agate
#

Ye

winter comet
#

a sub n

odd agate
#

1_2

#

No like with the math bot thingy

winter comet
#

oh

#

idk

#

💀

lime lotus
willow skiff
#

so how many units is (x, y) left/right of the y-axis?

winter comet
#

💀

willow skiff
#

corrected haha

odd agate
odd agate
#

I think either way it really depends on what you want the equation to represent

#

You could do an inequality to represent the area that contains all valid points

willow skiff
#

xy = 5

#

actually, |x| |y| = 5

odd agate
odd agate
willow skiff
#

like (0, -3) is still 3 units away from the x-axis

#

so basically |xy| = 5

#

that's the same

surreal crescent
#

Is directed distance the same as r?

wise ferry
surreal crescent
winter comet
#

if directed distance is like it can be positive or negative

#

then r can be positive or negative so it is A directed distance

#

but r is not defined as a directed distance and vice versa

#

i guess

#

i'm not really sure what you mean by are they the same

slim jasper
#

Is there anything I should familiarize myself with regarding Precalculus Algebra? I haven't had a math class in over a year, and old concepts have kind of slipped my memory.

slim jasper
foggy plover
#

ik factoring is a big thing in calc 1 and precalc so you def wnat to get that down

dreamy pike
dreamy pike
obsidian monolithBOT
#

ඞඞඞ

stiff sluice
#

please help

lime lotus
#

Am I right?

#

or wrong?

arctic dagger
#

I mean the computation is correct

#

Shouldn't be the 2 on the other side? Not sure

unborn saffron
#

could someone help me out with this somebody else asked me for help with it and i don't get it 💀

stiff sluice
#

Let $A = {(x,y) \in \mathbb{R}^2 \mid -2 \leq x \leq 3; , 1 \leq y \leq 4}$ and $B = {(x,y) \in \mathbb{R}^2 \mid 0 \leq x + y \leq 5}$, and let $P = (1,-1)$, $Q = (-2,2)$, and $R = (-1,3)$.
\begin{enumerate}
\item Determine which of the points $P, Q, R$ belong to $A \cap B$ and which belong to $A \cup B$.
\item Let $C = {(x,y) \in \mathbb{R}^2 \mid y = 2x}$. Find $A \cap C$ and determine if $A \cap C \subseteq B$.
\end{enumerate}

#

help

obsidian monolithBOT
#

ඞඞඞ

trim cobalt
#

Jesus

somber void
#

Can someone explain

#

,w d/de (e^x)

obsidian monolithBOT
somber void
#

why would it be 0?

elfin cargo
obsidian monolithBOT
elfin cargo
#

,w find the derivative of e^x with respect to e

obsidian monolithBOT
arctic dagger
somber void
#

no i mean d/de

#

maybe i don't know what e is and i have some iterative method to find it

#

and i want to know the derivative with respect to e

#

i mean it should be xe^(x-1), but why does wolfram alpha say 0

arctic dagger
#

It could be that it's treating the 2nd e as the euler's number and as a result, e^x is treated as a constant

somber void
#

oh

arctic dagger
#

And the derivative of a constant is 0

somber void
#

yeah that's probably what it is

arctic dagger
#

Otherwise just choose a different variable aside from e

arctic dagger
#

Ah yea that makes sense

#

,w d/df f^x

obsidian monolithBOT
arctic dagger
#

^here it gives the expected result. Just replace f with e. I conclude it treats the 2nd e as euler's number

elfin cargo
#

I don't know why Wolfram Alpha here won't work

#

You can get that by using Wolfram Alpha website

arctic dagger
#

Oh i see

viscid thistle
#

i think its confused

#

between the power rule

#

and the e to the power x thing

elfin cargo
viscid thistle
#

why is wolfram confused

modern carbon
storm lodge
#

its supposed to be d/dx @elfin cargo

elfin cargo
shadow ether
#

Not to x

#

It treats x as any random constant

#

And e as a variable

winter comet
#

he was saying it didnt work on discord but it worked on the website

shadow ether
#

Oh

#

My failt

#

Fault

#

Misunderstanding

winter comet
#

its confusing anyway XD

arctic dagger
#

Is it possible that discord uses a different version of wolfram alpha?

shadow ether
#

There are different versions?

#

Sorry I know I'm living in the past

slender vault
#

Lol

#

Y'all still going at it

shadow ether
#

Ur name literally q

#

Who u talking to

slender vault
#

I've been reading from the past day Ig

hasty lily
stiff sluice
#

wassup how is it going guys

#

I killed the chat mb

slender vault
stiff sluice
#

yeah differential of e^x with respect to e is 0

#

anyways

hasty lily
slender vault
#

Just say that it's d

hasty lily
#

Maybe they send different inputs to WA?

slender vault
#

Might've been the case

shadow ether
slender vault
#

e is a constant, and can you differentiate something with respect to a constant

#

I think it should be a variable

hasty lily
stiff sluice
#

lets use the definition of derivative as a limit shall we

#

,w d/de (e^x)

obsidian monolithBOT
stiff sluice
#

,align y &= e^x \ \frac{dy}{de} &= \lim_{h \to 0} \frac{f(e+h) - f(e)}{h} \ \frac{d}{de} \left[e^{x} \right] &= \lim_{h \to 0} \frac{f(e+h) - f(e)}{h}

obsidian monolithBOT
#

ඞඞඞ

winter comet
#

should be xe^(x-1)?

stiff sluice
#

I thought it was zero

#

can you show how did you differentiated

winter comet
#

the variable is probably just whats confusing

#

lets call e -> y, and x -> a

#

d/dy (y^a) right?

#

then you just use the power rule

stiff sluice
#

okaay sure

#

then?

winter comet
#

the power rule gives ay^(a-1)

#

do you want me to prove it with limit definition or?

stiff sluice
#

oh okay

winter comet
#

lol

stiff sluice
#

but catgod said limit def

#

wtf

winter comet
#

it gives the same result as using derivative rules

winter comet
#

oh he was saying taking the derivative of something with respect to a constant

#

in this case, we were treating e as a variable

stiff sluice
#

ye is constant

#

my bad I didnt said

winter comet
#

so ur saying why can't you differentiate with respect to e

#

huh

stiff sluice
#

ye

winter comet
#

i don't know how it follows from the 'limit definition' of derivative

#

but it does make sense with rates of change

#

the derivative just represents the rate of change

#

dy/dx means you look at how y changes as x changes

stiff sluice
#

ohh okay

winter comet
#

so dy/de means you look at how y changes as e changes

#

except if e is a constant, it doesn't change

stiff sluice
#

exactly, correct

winter comet
#

i'm pretty sure that just means dy/de doesn't exist

#

talking about how it changes makes no sense

stiff sluice
#

thank u for the explanation sir, yeah I was confused why = 0

#

also catgod used the derivative as limit definition yeah

winter comet
#

very unrigorously, i believe de would be 0 because its not changing

#

and dividing by 0 makes no sense

#

lol

stiff sluice
#

oh okay

winter comet
winter comet
stiff sluice
#

yeah when I saw that it was = 0 I shit the bed

winter comet
stiff sluice
#

ye

winter comet
#

wait a minute

#

it is 0?

#

hmm

stiff sluice
#

ye

winter comet
#

💀

stiff sluice
#

because rate of change mf

winter comet
#

i would think taking the derivative with respect to a constant doesn't make sense

stiff sluice
#

e is constant so no rate of change

winter comet
#

its a constant

stiff sluice
#

lmaoo

winter comet
#

e doesn't change

#

so this shouldn't be 0 it should be dne

#

it would be 0 if y doesn't change but e changes

#

😔

stiff sluice
#

if its dne why WA say its 0 doe

#

u sure bro

#

,w d/de (e^x)

obsidian monolithBOT
winter comet
stiff sluice
#

u see its 0

winter comet
#

i see its 0

#

ah you know what

#

it might be thinking of different e

#

taking the derivative with respect to the variable e

#

of e^x, this one is constant e

stiff sluice
#

is looking to differentiate with respect to e
and taking (e^x) as constant

winter comet
#

cuz the e font is different

stiff sluice
#

e is variable

winter comet
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its taking the derivative with respect to e of e^x

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notice the different e

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e is variable, e is constant

stiff sluice
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exatly

winter comet
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yeah

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and x is constant

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so is 0

stiff sluice
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lmaoo

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ye

winter comet
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it just misinterpreted 😂

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but yeah taking the derivative w.r.t a constant makes no sense

stiff sluice
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😂

winter comet
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im pretty sure

winter comet
shadow ether
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X is a constant

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So e^x

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Is also a constant

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Remember constant rule brother

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Wait dumbass

river drift
# obsidian monolith

note that the e in e^x is bolded, meaning it's euler's number, but the e in d/de is not, meaning it's a variable

shadow ether
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It took e as a constant

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And ur differentiating variable e

winter comet
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👍

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thats what it did

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thats where the confusion came from 💀

shadow ether
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Bro I swear every time I enter this channel

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Yall idiots always pondering abt smth

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When the answer

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Right In front of you