#precalculus
1 messages · Page 263 of 1
after u substitute 4 in for m, u get t
And that will be the answer?
t=.4m^2
u know what m is already
substitute that in
and then solve for r by doing 150+4t
plug t in
and thats r
I got 182
mmm lemme see
Thank you I appreciate it
thats what i got
which
You cant do difference of squares
It’s saying F of G
sorry gimme a sec
Plus I also gotta find if the function is even,odd and neither
Yeah it’s fine take ur time
I think you can say that
just havin problem solving for x or readin the graphs xD
Yeah lol
same opposite always positive
jan, how do u solve for x from Jpiggy picture
If this helps on the left side on the bottom that line is g(x) and the top on is f(x)
You cant do sum of squares tho
exponents adds
i dont get the piggy questiqn what re you ask?ng
Is the function even,odd or neither?
from JPiggy ss, how do u solve for x again
oh
Exponent raised by exponent is multiplicative
yeah
Yeah
Not additive
i thought it was additive vice versa for division and sub
can always just expand and group to check
Shortcut time 😎 😎
Yoooooo
I end up with
(s + 1)^4
I feel like I did something wrong
oof
So wait
u=s^3
Cuz (s^3 + 1) = (s^2 - s + 1)(s + 1) which is just (s + 1)(s + 1) which is just (s + 1)^2
i cant remember how but its like jan said, somethin to do w the cubic
I feel like I'm running in circles
Where did you get that
soap
ye
S+1 is my divisor
yes
,w factor x^9+1
:p
But it's not completely simplified
And if you do continue with this
You get something weird
Why is that
But why does that happen when we keep going
?
most numbers arent nice
i guess
most numbers are irrational iirc
at least reals
or something idk analysis
Noooo it happened again 😭
The far right parenthesis turns into (r^3 + 1) and it will go on forever
Wtf does that mean
,w graph x^6-1
This kinda annoys me wtf is going on
Am I the only one that sees the paradox
That it continues to go forever
Whyyyyyyy
And is there a rule that tells me to stop
When this happens
just expand out the equation
to 6x^5/x^4 - 6x^4/x^4 - 3x^3/x^4
then you can divide them all by x^4
so you get 6x - 6 - 3/x
and derive that
i think you did it correctly you just did signs wrong @terse ravine
what?
I'm confused
I still need help with this
f'(x)=6-3(-1)x^-2
f'(x)=6-(-3)x^-2
why do you just keep sending it over again]\
f'(x)=-3x^-2+6?
oops, im in the whole frong channel for this
nevermind I'll wait until I understand it completely.
too many are talking at the same time..
Well as a short summary: $$ (\frac{6x^5-6^4-3x^3}{x^4})' = (\frac {6x^5}{x^4} - \frac {6x^4}{x^4} - \frac {3x^3}{x^4})' = (6x)' -(6)' - (\frac 3 x)'$$
Tobii:

Yes. -(3/x)' = -( -1 * 3/x^2) = 3/x^2
hey could someone help me understand this answer
Determine the value that the function f approaches as the magnitude of x increases.
i see that the answer is 7 but im just a bit confused onto why that it is
moreover what the question is asking
So you're asking for $ \lim_{x\to\infty} 7 + \frac 1 {x-8}$ ?
Tobii:
yes
Well the first term doesnt depend on x so we can ignore that as it's constant. So we have 7 + $lim_{x\to\infty} \frac 1 {x-8}$
Well and that approaches 0
Tobii:
wait so i wanna ask first though is the question essentially asking for the horizontal asymptote of the function?
Yes
I didn't go over this with that rationale, I think: if x gets larger and larger 1/(x-8) get's smaller and smaller but never reaches 0
even if it would reach 0, it just never gets away from it again
wait also
the second part of the question asks "Is f(x) greater than or less than this function value when x is positive and large in magnitude?:"
the answer is greater than but according to what you're saying, wouldnt the value of f(x) get smaller as x increases?
because the denominator is increasing, making the fraction smaller?
f(x) = 7 + a bit
so it is greater than 7 (the value just determined)
it gets as close to it as you want to though.
wait so 7 would be the function value and the horizontal asymptote?
yes
well not the function value
the function value would be f(x) which is always a little greater than 7
But I guess they refer to the asymptote as "this function value"
Could be I'm completely mistaken :'D
Is there any more context?
uhh i dont think so
im not too good at mathj
this is all it provides
as far as i can tell i dont see any other context
Well seems like I was not mistaken after all
so are you saying like in a normal circumstance, the function value and f(x) are just the same thing?
ohh ok
im native and i dont understand any of the language part
probably more than you tbh xd
ok as a final question, i jkust want to ask, when generally we say as x/f(x) approaches [some number], are we just describing when x/f(x) is just approaching an asymptote?
not really. That works as a picture in this case as we go to infinity, but you can also approach specific values, like points where the function is not defined
like 8 in your example f(8) = 7 + 1/0 which is not defined
but if we go very very close to f(8) from the right or left we can deduce some information about the function
but that is probably calculus stuff or comes later on
oh wait wait actually last question my bad
so how could x go to infinity if the vertical asymptote is 8?
or is that just an expression for x increasing
your input value can be as large as you want
so is it just a discontinuity at 8?
well we could figure that out by approaching f(8+e) and f(8-e) with e getting very small. If those match up there is literally just a hole there
otherwise the function might jump at that point
,wa f(x) = 7 + 1/(x-8)
Hole pole
first of all read #❓how-to-get-help @thorn plank
secondly, its barely comprehensible
what the actual fuck were you thinking trying to PING EVERYONE in a server of THOUSANDS, @thorn plank
<@&268886789983436800>
seriously you're directed to #❓how-to-get-help when you join this server
bruh
my bad mods if this wasnt ping-worthy kindly forgive me for my terminal stupidity
derivatives are taught in high schools right? so early uni calculus wouldnt be the spot to post on for me rn
it depends
is f'(40) = 800 on this graph?
what would f'(40) then be? 0
yea
aah okay, thx
logarithms are too exponents as inverse trigonometry functions are too __________
what would this be
Why do u care if he pings @everyone
Oh nice it doesn’t work
shut the fuck up
bitch
These were not acceptable
okay for 1) try to write the trig functions they want (cos, tan, csc, cot) in terms of the ones u have the values for (sec, sin)
drawing a triangle helps
then apply pythagorean identities and signs in quadrants of the unit circle
"At a point 150 fett from the base of a building, the angle of elevation to the bottom of a tower on top of the building is 32 degrees. The angle of elevation to the top of the tower is 50 degrees. Find the height of the tower alone."
How do I do this?
Like I am pretty lost with i
it*
draw diagram
have you made a diagram? @viscid thistle
i made one rn but i only have it set as a right triangle, and i think the 150 would be the bottom part of it? like it is one of the sides that aren't the hypotenuse, and it isn't the height
it's the length part of it for me if that makes sense
so is the angle at the top 50 degrees? or is it the 30 degrees?
try making a drawing of the actual setting
this is what i have got
where's the tower?
the one thing with the door lol
oh there are two different stuff?
Can square root of 181 over 9 be rationalized ?
$\frac{\sqrt{181}}{9}$ is already rationalized
Ann:
oh okay so there is nothing you can do with it?
hypotenuse over opposite
no, what are you trying to do with this number?
181 sq is hypotenuse and the opposite would be 9
find the csc value
i am asking you, what are you trying to do now that you've got this number: sqrt(181)/9?
what are you trying to do with the expression sqrt(181)/9
I'm wondering if that is my answer
i don't know, you haven't posted the problem
so nobody can tell you whether or not sqrt(181)/9 is the answer to this mysterious problem, which it seems you expect people to magically know about
Use the Pythagorean Theorem to find the length of the missing side. Then find the trigonometric function of the given angle. Give an exact answer with a rational denominator. So I got a triangle the opposite side is 9 and the other side is 10. So I needed to find the hypotenuse which I did which is sq181
you mean sqrt(181)
okay, so like
you're asked for csc(θ) where θ is the opposite angle to the side with length 10
yes your answer is correct now
it goes through 2, 5, so x = 2 and y = 5
substitute and evaulate
and then take the square root of the result
@hazy furnace find the radius of your circle
this is what they're trying to do, yes.
idk how to do that
I just explained it
explaination was poor
thanks, so am I
apply the distance formula
idk what that is
look it up
ok
why are you making this more complicated than it needs to be
plug in 5 for x and 2 for y, evaluate the expression and take the square root
I'm not sure how that explanation is poor
how i evalute experssion
that works too I guess
Result:
73
dont even need to take the sqrt
yeah
since you're not explicitly after the radius
only to then square it immediately afterwards
I didn't read the question properly, I just saw that they were asking for the radius

i dont understand how u get 2-5^2 + 5+3^2
parentheses!!!
idc

()()
the circle goes through (2,5), so naturally, plugging those values in for x and y needs to result in an equation which equals the radius squared
as the circle equation is the equation which all points on the circle have to satisfy
,calc (1-4)^2+(5+3)^2
Result:
73
,calc (-3+1)^2+(2+3/2)^2
Result:
16.25
You can also use desmos :+1:
not sure which channel this belongs in, but what is the sum from k = 1 to n of k^4?
$\frac{1}{30}n(n+1)(2n+1)(3n^2+3n-1)$
Star_:
Oh I forgot the 36x^2+48x+16
Then f'(2)=(10) / (36(2)^2+48(2)+16 = 5/128
Never mind, was a mistake in typing out the correct ans. Sorry, for pinging :c
I've been doing Math for 8 hours already x.x
What are the extreme points of x/(2-sqrt(x)) ? I found x=16 as maximum but in the book it's says there is one more point which is x=0
,w d/dx x/(2-sqrt(x))
But why? How can I find it algebraiclly
Extremum points occur where the derivative zero, or at the boundary points of the domain.
if a rational func has variables of even degree then it doesn't pass the horizontal line test and dosn't have an inverse
is this statement correct?
use the fact that $e\approx 2.7$
Anonymous:
is there a way to find the extrema of a quartic instead of just plugging in numbers between roots
take derivative and find zeros?
without derivatives cuz i feel like my teacher wouldnt appreciate me using concepts we havent learned yet
yeah he kinda just told us to graph a quartic function and describe it, and he always wants to know the extrema and on the answer sheet he has the extrema, but doesn't show how he got to them
$\pi$
boof:
$e=\pi=3$
boof:
Yes this is cursed
very cursed

@polar heart why is e approximately 2.7?
because it is
i get that but can u show the work?
like how does that have anything to do w approximate values from a list of numbers
I cannot say that I can fully explain it to you, if you want a comprehensive answer check out Eddie Woo's video.
eddie woos?
it pops up in a lot of places and can usually be traced back to being related to exponential growth
he used a calculator, but the hw says not to, so is there a way not to use calculator or do u have to use calculator to solve for this
could I see the full question? I'm curious now
the one i posted above is the full explanation to the problem
they give u a list of numbers, and find e-1
Oh, they clearly just expect you to know that e is approximately 2.7
Thats what my first thought was too
I think that they're testing your knowledge of the approximate value of e
thats weird but ty yall
whats with the list of numbers tho?
like is it important in any way
I dont think so, it looks to be a set of options for you to choose from
Yes, they want to limit the correct answer to one. Otherwise someone who uses e = 2.7 and someone who uses e= 2.718 will enter different answers. Now you just have to choose the closest value in the list, so everyone has to choose the same one
It would be less confusing if they just asked
"What is the approximate value of [ e - 1 ], round to one decimal"
i see
π=e=3
so 2pi is a full rotation, yea?
and the negative means were starting at (1,0) and going anti clockwise
so were almost going a full rotation anticlockwise
youll land at a place where both the x and y coordinate are positive
so all you need to know is if the ratio of a positive number and a positive number is itself positive or negative @minor pivot
yea
its 1 where the signs match
(of the x and y coordinates)
and -1 where they dont
oh so if the question was 7pi/4 it would be -1 right?
yea 😄
thanks
It’s interesting looking at this channel. The US system is jarring for me- why do you wait till University to do some calculus aside from precalculus? The nature of the questions you get is also weird. Though perhaps it’s better- my country’s course infamously scars the mental health of most students and suicide isn’t uncommon.
Perhaps I should have said this in a different channel
anyone free here for a sec?
can someone explain why 10 is wrong
all i did was 4.67 divide by 4 because it is quarterly, then i got 1.1675. divide that by 100 turning it into decimal rather than percent and it becomes .011675. add 1 to that=1.011675. take that to power of 6 and multiply it all by 1000. where did i go wrong bruh?
to sum that all up
this.
@quaint mason it's 6 months but 1.1675% is the quarterly interest rate, so you'll want to do this for 2 quarters, not 16.
wym i didnt do it for 16 quarters
you say you raise it to the 6th power but then write 16 in the pic, which is a bit 
^
you're already writing it as a superscript, why insert a caret
idk
...
anyway the exponent should be 2
i actually
for 2 quarters
,calc 1000 * 1.011675^2
i caught the mistake
Result:
1023.486305625
1023.49 is wrong?
oh wait wow
my calculation is wrong
not that
ah i found out what i did wrong
for some reason my mind kept thinkin it stays 1.1675 even tho ik im suppose to do it the way i described...
sorry thats my calculation error
thank you :)
thats right, ty :)
Can someone please check my work and help me understand how to do question b.) and c.)
asap please cause i'm trying to review for my upcoming test
ty
really?
i thought it was asking me to find the angle of the coterminal
isnt the coterminal of -pi/4 = 7pi/4
and the angle of 7pi/4 is 315?
and -315?
yeah i understood dw lol
i'm either
overthinking or
doubting myself
so should i just leave it at 315 degrees
-315 degrees isn't coterminal with 7pi/4?
gotcha
and while i have you here
in the midst of my breakdown and overthinking crisis
this is okay?
Actually there are two answers here
+315 works too
When going clockwise, you go in the negative direction
ah equal
And that gives you -45
When going counterclockwise, you get the equivalent positive angle
I wish i can draw a diagram here
But im on mobile
i drew it out a couple of times to make sure im not going crazy lol
(the mathematicians and clockmakers definitely had some kind of dispute in there)
i think im going clockwise
I woukd say negative and postive direction but thats a bit counterintuitive and confusing
lemme post my diagram
oops
lemme flip it
okay
it has to be 315
since it's going counterclockwise
thank you guys
No problemo
yikes
not correct
it was only -45 degrees apparently, not 315 degrees
which doesnt make sense to me
Well, when not considering the range 2 pi, but in general, it could be illogical to say that -pi/4 = 7pi/4
So its not entirely confusing
But i guess they were looking for a specific answer
it's all good brother
@fiery wren just wanted to correct something i stated before, coterninal angles can be found only on 360n+theta
kin:
same thing
by log rules
remember that $a\log{b} = \log{b^a}$
and in particular log(1/x) = -log(x)
Little Narwhal:
👍
Hmm:
Hmm:
$\frac{A}{x+3}+\frac{B}{3x-1}$
Yeah, then solve for A and B
Can someone please check my work and help me understand how to do question b.) and c.)
asap please cause i'm trying to review for my upcoming test
ty
I asked this question yesterday but again someone else asked a question right after ans no one replied to me wth
I would greatly appreciate if someone could help me
what you did in a) is what you need to do for c)
in a and b you just need to say that it's $64 e^{\frac{13\pi}{6} i}$ raised to the power $\frac{1}{3}$
ConfusedReptile:
didnt you forget to apply the 3rd-root to the e-term?
They did divide 13/6 by 3.
oh right, I totally missed that
I did apply the third roof
Roof
Root
So I got 13pi/18
I don’t understand what powder the complex number is raised to
1/3?
Or do I saw the 13pi/18
Yes, 1/3.
How do you do this?
<@&286206848099549185>
Still need help for this one problem I really just don't know how it's done
First time seeing that symbol
Can you expand sin(x+φ) using the compound angle formula for sin?
Then compare what you get to what you have to rewrite
No, e here is the Euler's constant, the base of a natural logarithm, approximately 2.7182818284590452353602874713527 😛
how do i solve for a and b?
use the fact that $e^{n m} = (e^{n})^{m}$
ConfusedReptile:
KO7S:
Compile Error! Click the
reaction for details. (You may edit your message)
KO7S:
yes
my question is "solve the equation on the interval of 0 <= (theta) < 2pi."
the equation is cos(3theta) = 1
for some reason, the answer isnt 2pin/3
Cuz theta is restricted to [0,2pi)
so n=0 is the solution
for some reason, the answer isnt 2pin/3
$14.825 e^{-0.007t} \approx 14.825*0.99302^t$
ConfusedReptile:
Well you could start by calculating the first 3 entries of the product... You should see where you are going from there
wait
you could add all the entries into one row
then take that out
then you'd be left with ones
then you'd subtract every row from one another until you get just one in the row with the ones
then you take the determinant of that
Why do I think, that he just came here to get the solution to his homework from somebody?
@stoic fox
yes?
these are both 10 by 10 matrices, do you think their product could be undefined?
thats exactly the reason why i said "if it exists"
have you ever multiplied two matrices before
yes sir
The product of 10 by 10 matrices always exist, so you don't need that qualifier. So that's exactly the reason you don't need to say that.
What makes you think someone named Ann is a sir?
"sar"
also yeah don't call me sir please
anyway multiplying two 10 by 10 matrices by hand is painful
And it might not exist
The villager way of saying "sir" since u guys didnt like it
use wolfram alpha
no @viscid thistle stfu
the issue isn't that we don't like the term "sir" it's that i'm not a man lol
LOL
how's that relevant
well i am 23
why are you doing precalc at the age of 23
i'm 21 but again how's that relevant to my not being a man
why are you doing precalc at the age of 23
@viscid thistle What can i do sar
why are you doing precalc at the age of 23
Why not? Don't be rude
Why not? Don't be rude
@echo wagon thanku sar
Please stop calling people sar and sir. It's p rude to keep doing it after you were called out. You don't know who is male here.
if you insist on using "sir" or "ma'am" for me i'd rather you call me ma'am
Ok madume
And I am male, but I don't like sir. And I'm younger than you, so it's extra weird
Ok madume undarstud
...
...
computing their product will literally take a thousand multiplications
checks how long he has been on this server because this has to be a troll post
Lol, you say you know how to multiply matrices, you're just too lazy to do it. So now you are asking us to do it. Ridiculous.
Why u so lazy then
you expect me, a random stranger on the internet, to sit down and do literally 1000 multiplications BY HAND for you?
Use an online calculator
and i'm the one who's lazy?
how were we meant to know
So your whole post is a troll post?
we aren't telepaths, we can't read your mind
the function is y = 0.19cos(pi \7 x)+1.62
yea i used a calculator to find the derivative of function xbetween zero & 24
but on the answers, there are 2 sets of answers, one using only the max of the derivative graph and 1 using both the max and the minimum
which would be the correct one?
Do they give two different answers or two methods to get the same answer?
yea, its the same method, 2 sets of answers
but one teacher uses both the min & max and one only uses the max
Show us?
anyway @stoic fox if you still want that product
Pink is correct @delicate rivet
okieee tysmm,
The sign of the derivative only indicates whether the tide is increasing or decreasing, not the speed at which it is doing it.
So you want the biggest magnitude of the derivative, without caring about the sign. So when it is + or -
thank you again!
Np
amy.ames.aims:
nvm i figured it out
math sucks anyways
math sucks anyways
@WaidenWolf#6153 what is cool in your opinion?
They left. Lol
product rule
Hi guys, I need help with difference quotients and rational expressions
More specifically I'm struggling with finding the difference quotient of rational expressions with square roots
do you have an specific problem that you are stuck with?
Yes, f(x)= -sqrt of 8x-35
I know that f(x+h) is -sqrt of 8(x+h)-35
and I know how to set the equation up, but I get lost with the correct terms that need to be figured out
what do you have atm
(-sqrt8x+8h -35 - -sqrt8x-35)/h

just to be clear:
$$f(x) = -\sqrt{8x} -35$$
right?
ramonov:
$\frac{f(x+h) - f(x)}{h} = \frac{ -\sqrt{8(x+h)} - 35 - ( -\sqrt{8x} -35)}{h}$
ramonov:
howdy yall, here on question b im struggling to find out how to implement the perimeter as an expression in terms of l.
bc i feel i somehow have to add (length2)+(width2)=335 somewhere in here
but g is asking for area...
area = length x width
well yeah, but how do i show that when (length2)+(width2)=335
Note that you're essentially asking the question: "how do I separate $w$ when I have the equation $2l+2w=335$?"
Rijinaru:
Does it help you when it's framed like this?
to a degree, im just not sure how w fully disappears since it cannot be in the final expression.
Are you aware that $w= (335 - 2l)/2$?
Rijinaru:
ramonov:
@obsidian monolith place the -35 under the radicand and then simplify it further
@uncut mulch
-28
How would I go about this since i just got x=54 and other two x=0
What?
oh okay
yes
i tried vietas already cause it is a similar problem but they didnt really work
What did you do
8?
m = -2(-1/2 + 4) = -7
-2 = pq^2, 2 = 2pq + q^2
pq = -2/q sub into second equation get a pretty easy cubic
pretty hard precalc prob tbh
Hard ?
i am
Same
I do not expect school to give this type of prob
Its not school its extra curricular
welp
my mistake was that i used an-1 subscripts from the wrong sides so i was using the wrong coeffs
so close yet so far :((
smh
yes
yes
@steel venture so -(bp/k)+4?
yes
thank you
Could I have help for my practice test?
So then I could ace the math test I have tomorrow
did you already attempt it?
I have attempted partial of it but parts I am stuck on
go through the whole thing, preferably in a test environment first
and we can guide you on what you missed / need to work on
sure
That’s the first one
not really pre-calc
....
When you want to isolate for a term like b, all you need to do is do the backwards operations of PEDMAS
or BEDMAS
or whatever it is in your educational system
Yes PEMDAS
but where did you get stuck?
On the adding... of -2 lol
consider adding 2 to both sides
Okay I did that but after that is what I got stuck on
$\frac b4 - 2 \red{+ 2 } = -1 \red{+2}$
ramonov:
what do you have after that
Think of it this way
$+2-1$
AbooZinho:
You're left with $b/4 = 1$
AbooZinho:
B=4?
lowercase b
Well yeah... sorry I’m dumb
to get from b/4 to b, you could multiply by 4,
so you could multiply both sides of the equation by that
THANKS
Okay thats actually sooo helpful
I know im not too bright..
I think I know how to Ace this test tomorrow thanks!
timour:
x = 2e^y - e^{-y}, solve for y
I saw a proof for the associativity of function composition, can someone explain the reasoning behind the steps marked with (?)
This is how Tao wrote them 
weird
Should I quote the definitions too?
brhu
Nope, none of these lines is mentioned in the errata(although another line from the same proof is).
Aight one screw up on my end 😅
Sowwy
This just looks like we assume what we want to prove
How does the third step move to the fourth?
f(g(y)) = (f o g)(y) where y = h(x)
Hmmmm this makes more sense.
But I'm not yet entirely convinced about how this argument is working, I know it should be true but this symbol pushing feels weird.
Is there an alternate way to prove it? Perhaps by using some arbitrary elements?
it should be obvious that applying (h, then g), then f and applying h, then (g, then f) should give the same result tbh
Oh, okay. Thanks!
im not sure if i understand this
does this just mean that if 0 < |x-5| < delta = epsilon then 0 < epsilon because |f(x)-7| = |7-7| = 0 so |f(x) - 7| < epsilon ???
Does anyone know how to do the integral of cos^6 x sin^3 x dx ?
Have you tried something?
consider trying to identify the parent function by it's looking and then apply their function transformations
I got it, I messed up on a trig identity
@misty ocean arccos(-sqrt(3)/2) = 5 pi/6 =/= 7pi/6 hence the first statement is true and the second is false. This is from the fact that cos(x) is not injective as several inputs corresponds to the same output, i.e cos(7pi/6) and cos(5pi/6) is both equal to -sqrt(3)/2
being injective means that for all x y in some domain is a set S, then f(x) = f(y) => x = y
why cant t <0?
Then t = √[x/21]
And you don't need to worry about the negative sqrt
it is just x-3
this is stupid. why tf is that question here.
confusing me by taking me back to 3rd grade
istg
no

