#precalculus
1 messages · Page 64 of 1
so 2 * 2 / 2 * 2 * 2 * 2 * 2?
yeah there we are removing 2s instead
we are simplifying the twos we have on top and the bottom but the bottom will still have 3 left
1sec
what's your main language?
like i see how the result is the same, but havent we subtracted 4?
swedish
we did not subtract 4
you can say that we divided by 4 both on top and on the bottom
well that doesnt rly explain the problem because then it would also involve applying it again so nvm
but yeah for example 2/7
lets take ugly numbers
if you multiply both the numerator and denominator by the same number
you still get the same ratio
4/14
yeah, since u scale them relative
yeah, that brings me back lol
if i said that 1000 meters is 1 km
4000 meters is 4 kilometers
doesnt change the fact that 1000 meters is still 1 km
yeah, i guess i just have to think about division as fractions (bråk in swedish) and not as a value if that makes sense
yes its best to start looking at divisions as fractions
and then simplify
(they are the same thing)
yeah, and with fractions you can simplify too
which makes it a lot easier
it is definitely way easier
okay, ill have to look over this tomorrow, but it makes more sense now
but you can do it with division too technically
this really helped. i also have a question
we just use fractions after instead of the : sign
what do you mean?
idk if you know about khans academy or if its good etc, but i have these bookmarked in order. does this make sense? (thought, pre calc should be before calc bc)
think at the beginning division is taught using the : sign or at least where i live
like 10 : 5 = 2
but after we just use fractions
it has the same meaning
10/5 = 2
ah, yeah, same here, but forgot about that since its very early on
havent used that for like 15 years xd
trig def after algebra stuff
precalc yes before calc bc
okay, ive had a linear algebra course and passed, but mostly just because i memorized patterns
think differential equations you can do it aftermultivariable but i myself havent learnt that stuff yet
matrices and linear transformationsv
?
yup
i'd recommend watching 3blue1brown videos for that
explains it very nicely
i rewatched it like 5 times to fully understand it
however, i mainly know how to apply the mathematics, but theres a lot i dont understand on a deeper level
yeah, he's great
usually this stuff is taught in uni
i understand how the cosine funcs etc (SOH CAH TOA) returns what they do, but a lot of other stuff i dont get on a deeper level
ay never too late for math
yeah i know. im a software engineer, mostly focused on 3d rendering where you mostly just use applied linear alg (matrix transforms, vector maths like dot or cross product). but ive come to a point where i need to learn calculus and more advanced math to read papers etc since a lot uses derivatives and integrals
concept of derivative is not too hard to understand
integral kinda harder to explain why formula works
yeah, i understand the concept, but most papers use math heavy notation
Khan Academy is how I learnt calculus :)
https://youtube.com/shorts/PGK-RXA8Ye8?si=UnZqBu_WxF9yBRas quick brainrot video explaining it
⚠️DISCLAIMER⚠️: This is not real celebrity audio/video. All video and speech was generated to help others learn about maths, physics, and engineering.
actually needed to re-learn algebra tbh
stuff they taught in school wasn't really thorough enough or maybe I didn't pay attention
@inner topaz regardless, thanks for taking the time to explain. ive got a lot to learn and ill hopefully stay dedicated
no problem!
too much brain
yeah, now you see why ive hit a dead end lol. if i wanna evolve my skills and learn more advanced rendering techniques, ill need to understand this at some point
makes sense
cause its really frustrating visualizing ideas, having the coding knowledge of implementing it, but not being able to simply because you suck at non-lin alg math
yea
usually people dont even solve it they just let some software and stuff do it no?
power of wolframalpha or graphic calculators
a lot of people just steal a formula and adapt it to programming. ive done that before too. but the problem is when you need to actually understand the maths behind the formula, or even the formula itself. in comp sci and render-related research/techniques it can be very heavy math notations as you can see.
you might need to understand the formula if you wanna extend it or change it. you also need to understand the math if you wanna be able to create new formulas
ex. you wanna scale something between 1 and 0 based on a max distance of 5 in a certain way. then you can use this and just replace the variable x with the distance:
this is simple, but you might want a more complex response which requires you to be good at math
His differential equations series is buns
how can i simplify this expression?
ignore the lim, thats part b. i just need to simplify the sin(x+1) / sin^2(x-1). the denominator expands to sin(x-1)sin(x-1) which doesnt cancel with sin(x+1)
Help me with No.3 and No.4
For question 36 isnt there no point of inflection? The answer key says its B tho
someone pls help it is very late i need to solve this (second pic is my work)
nvm i have the anwer
think it's sin(x) + 1
any context behind it? id like to understand too haha
$\sin^2 x - 1 = (\sin x - 1)(\sin x + 1)$, difference of two squares
south
also if it really was sin(x+1)/sin^2 (x-1) the function would be continuous at 3pi/2 so just plug in the values
yeah like that's a completely different thing that can't be simplified
sin x + 1 always means just (sin x) + 1
got damn im more confused than ive ever been before
$\sin x + 1$ means $\sin(x) + 1$ by the way, not $\sin(x+1)$.
ann.in.a.teacup
this is why you should always put parentheses around the inputs of trig functions
so its actually... uhhh... hang on lol . "sin^2(x) + 1" ?
my brain is melting and dripping out of my nose
yes
in the picture they mean sin^2 (x) - 1 though
if this is happening for realzies you need to be calling 911 ON THE DOUBLE.
or 112 depending
emergency services
it's figurative lol
so its Sin(x)Sin(x) - 1?
sure yes
yes
(sin(x))^2 - 1
why is this notation so confusing
it's like if I write cant
I mean can't = cannot and not the noun cant (a secret language)
it's similar with mathematics; some brackets don't need to be written cause they are implied
don't you know the order of operations? pemdfas
in particularly the brackets around x for trig functions, so tan x, csc^2 x, and so on
i know thats where f shouldn't go but it sounds funny 💀
except that in my opinion writing sin x is just bad and looks bad
that's just your opinion though
i agree though
yeah but it's a correct opinion, because that's all the opinions i hold. 
if you apply a descriptive rather than a prescriptive approach to the way people communicate
people absolutely write sin x all the time
i hope it is clear that i meant the last message in a sarcastic if somewhat self-aggrandizing way
ok so the denominator is actually a difference of squares BECAUSE similar to x²-4, its like Sin(x)² - 1.
thus, it factors to Sin(x) - 1 and Sin(x) + 1
whence the
emoji
that's why mathematics is a lot of the time about communication
people can also write 5/4/3 . . .
you don't want to write something that is ambiguous, that's true
it factors into (sin(x)+1)(sin(x)-1) yes
but they shouldnt...
yeah that's when it's ambiguous imo
damn i start to have a stroke when i try to insert trig into algebra hahah my brain is very smooth and reflective
be lazy with brackets, in the right way
if not (5/4)/3, then at least write 5/4 / 3
the space helps a ton
technically its not, from what i know the order of operations goes left to right when you do operations at the same priority
but yea
I know but then that's just bad communication imo
a lot of this is based on how others communicate
it's very subjective as you can tell
i would just try to leave it as unambiguous as possible
without doing too much extra work ofc
💀
Js get rid of fractions atp 🙏
yes, finally that's correct
,w 1 divided by sin 3pi/2 - 1
made a little cycloid animation in desmos. I realized there’s no calculus involved, so I guess I’ll share it to this channel https://www.desmos.com/calculator/5yxenbv39u
no but actually i agree, sin x is horrible
we ought to be concise as possible and NOT omit any parentheses for function calls
Haskell's philosophy disagrees with you
im sorry but haskell is for NERDS..
Is my Inductive step correct? For question 10
correct so far!
Oh I was worried about the (2k+1)²+(2k+2)² the most lol
Thx south!
wtf is this
i didnt get a single clue of what was being said
why is e involved
thats my main confusion
why tf is e involved 😭
look at what yall are doing above makes me feel so dumb 😭
euler's formula
Well you're looking at imaginary numbers; numbers of the form a+bi, where i = root(-1).
We can plot this numbers on a plane known as the "argand" or "complex" plane. Basically, you plot a point with 'a' as the x axis, 'b' as the y axis.
Join this point to the origin (0,0). The angle made by this line with the x axis is known as the "argument" of the complex number, usually denoted by θ or φ. You can use trigonometry to evaluate this argument (tan(arg) = b/a).
Euler gave us a formula telling us that any complex number (a+bi) can also be written in an "exponential" form: re^(iθ), where θ is the argument and r = root(a²+b²).
This exponential form is equal to a+bi, i.e. a+bi = re^(iθ)
look what happens when we multiply two complex numbers together in polar/exponential form:
$$r_1 e^{i \theta_1} \cdot r_2 e^{i \theta_2} = (r_1 r_2) e^{i (\theta_1 + \theta_2)}$$
so, the angles add and the magnitudes multiply
that's exactly what we want from a complex number!
south
(there's a formal derivation using Taylor series; if you want that just search up e^(ix) = cos x + i sin x derivation online)
Is $\int \frac{\Delta y}{\Delta x}=\frac{dy}{dx}$ or $\int \frac{\Delta y}{\Delta x} \neq \frac{dy}{dx}$
Sapphire (Stacie)
Oh I forgot that $\Delta x$ has $\lim_{\Delta x \to 0}$
Sapphire (Stacie)
Neither
Integral of a derivative will give you the initial function due FTC
The lim as Δx goes 0 of Δy/Δx is y' or dy/dx but do not consider dy/dx as a fraction
can anyone explain how to do gauss jordan elimnation using matrices?
This precalculus video tutorial explains how to perform elementary row operations using matrices.
Matrices - Free Formula Sheet: https://bit.ly/3UE9Cmk
Introduction to Matrices:
https://www.youtube.com/watch?v=yRwQ7A6jVLk
Adding and Subtracting Matrices: ...
Definition of elementary matrices and how they perform Gaussian elimination.
Join me on Coursera: https://imp.i384100.net/mathematics-for-engineers
Lecture notes at http://www.math.ust.hk/~machas/matrix-algebra-for-engineers.pdf
Paperback at https://www.amazon.com/Matrix-Algebra-Engineers-Mathematics/dp/B0BJYMGT6S/
Subscribe to my channel: ...
I don't know what you mean
does the 2nd video help?
Hey I’m doing this problem and I am asking if the 3 of 4x/3 is apart of the hori stretch or is it a left right transition
it's not a translation! a horizontal translation would be f(x - a) or f(x + a)
it's a compression, so a horizontal compression with factor 4/3
that's also a horizontal stretch of 1/(4/3) = 3/4
Ohhh
yeah
how do you solve this: 3sin(2x) + 2sin(x) -3cos(x) = 1
with like only the pythag, sum and difference, double angle, and half angle identities
for domain of all reals
(1-i)^2=1-2i+i^2=1-2i-1=-2i, then sub that in I think
3(2sin(x)cos(x)) + 2sin(x) = 3cos(x) + 1
2sin(x)(3cos(x) + 1) = 3xos(x) + 1
2sin(x) = 1
but that does mean cos(x) can't equal -1/3
What does undefined mean in math? does it mean that something tends to infinity? or smth
it means that it has no meaning
yeah maybe you're a right
turn it into re^itheta
isn't that overkill, because (1-i)^96=(-2i)^48=(-4)^24=whatever that is
when i put ts(x) isnt the result supposed to be 3-3/x+1/(3/x+1)? markscheme says 3-3/x-1/(3/x+1). Markscheme is on the right
nah
i mean turning it into re^itheta works for pretty much anything
and it doesnt come out ugly too
$\sqrt{2} e^\frac{i\theta}{4}$
$\sqrt{2} e^\frac{i\pi}{4}$
Ryse
idk why i used theta
sqrt2 to the 96 is nice
e to the whatever is nice
imaginary part cancels
real part becomes 1
it's generally the normal way to do it
wait but if you divide the cos instead of the sin then you would end up with cosx = -1/3
and then the sinx answers cant exist
I think what's going on here is that it represents two mutually exclusive sets of answers
x=sin-1(1/2) or cos-1(-1/3)
but not at the same time
both work when subbed in
yea i looked on desmos it says all answers exist but im confused as to why
cause the sin solutions only work when cos is not -1/3 but my cos answers only work when they're -1/3
I think its just that there are two answers, when you divide by cos, you are stating the cos is not -1/3 and vice versa
Damn.. y’all really mathematicians
BRO WHAT R U DOING IN EVERY CHANNEL
Idk 😭
just like your username
,w incessant
Is the blue line still a asymptote ?
By definition it should be, right ?
yes
the asymptote occurs when your graph is unbounded, but it doesn't care about the other parts of the graph
like for horizontal asymptotes, the asymptotes can intersect the graph at places lol
I don’t understand how sec is on the 2nd and 3rd quadrant
maybe it's not sec but the angle x
can someone help me find practice problems like these, id really appreciate it
I could give you some later.
Give me some moment.
ok thank you so much
Yeah
I believe I could only give the trigonometry one.
Because that's what I have here.
im fine with that
yea my test is tomorrow
Where are you from?
dawg just give me the question
Then sadly I can't help you if it's that urgent.
I need to know how much time I have left.
The book is at home.
ohh
While I'm outside.
ok understandable
Yeah sorry.
no its fine i thought u were just avoiding giving me the problem
In the meantime, you can have a look at this first.
ok tysm
Welcome.
btw i would probably have like 2 hours left max
discrete maths
i just mean like 2 hours before i go to bed btw
prob like 30 min now
and within that we neeed to know abt sequences and series, matrices, vectors, and proof by induction
Wow.
y wow
Nothing.
quick question: if i had a circle radius 4, would the horizontal displacement of the angle measure pi/6 be 2sqrt(3)?
yes
thanks
will 2 days to study for my precalc test be enough
depends 
2 days of weekend lel
nah tuesday nd wednesday im clueless ab it rn its like vectors tho is that hard
idek
most likely not too hard but
hard is subjective :l
so what u think
its possible if u lock in fr
its cooked huh
but its a half test i dint expect him to give us one bro
really just depends on what you can do and what they give you lol
but atleast it's only worth half the points
and i know neither so...
and tips on studying?
bro 💀
yeah bro jus try n get it done
thursday my birthday too he knows what he doing
imma try to ask some sweats if thats the method
ayy 😭 well happy birthday man
thx
i mean
the main thing is you wanna get it done and not be doin other stuff (like thinking about whether you should be getting it done?) 💀
jus gotta lock in on it frfr
i mean i got other work to do still
yeah
js gotta thug it out bru
mhm
It would be a Yes for me.
alr that means its free for me if yes for u
nah im js playing thx
should be possible at least
is it just me or is this a terrible way to describe this equation... https://i.imgur.com/ii3qRjm.png
how can they not say what to add 9 by
Wouldnt "square, add 9" mean x²+9?
nah because that's not what it says, it says take the square root
Yea but the literal first word is "square"
Root(x²+9)/7
no it's not, the first word is add
maybe it's a cropped image
😆
Mbmb
I don't think it's terrible. it's like implied you're performing the operation step by step to a given variable (x)
I guess. Never seen it before though.
it's fine, they're just leaving out mentioning your input number. Like we could describe the function f(x) = x + 9 as simply "Add 9 [to whatever you input is]"
I’m doing matrices for precalc and I was wonder does the x in 2x=3(e+f) needs to have the two removed are does it stay like that?
if you're trying to solve for x then you'd divide by 2 yes...is there more context to this tho...
oh yea you'd want to divide by 2 to get X alone
ok
Did I get x by itself right?
Hello everyone
Please does someone know a good youtube video where I can learn Curve Sketching?
To sketch functions with range and domain can i use a table of values? like say from x=-3 to 3?
yes
For the part b i wrote the range as y>1/9 but markscheme says y<1/9 and for part c i wrote the domain as x>1/9 but markscheme says x<1/9 .My question is why does the sign change?
the sign flips when you take the reciprocal
given that x > 4, x + 5 > 9
and now 1/(x + 5) < 1/9
it's like how 2 < 3 implies 1/2 > 1/3
this comes from $a > b \implies \frac{a}{ab} > \frac{b}{ab}, \frac{1}{b} > \frac{1}{a}$
south
Oh I see. Does it only apply to the reciprocal?
there's a lot of other functions too
it applies to any decreasing function
If only life was that simple..
1/x is always decreasing for example
no worries!
never.
WHAT!!
if you wanted to reflect y=x^3 across the line y=x would it become y = -((-x)^3)?
if y = x you literally swap y and x
This is equivalent to the inverse, which is ||³√x||
I havent taken precalc just trig and algebra am i cooked
what is coming up in your immediate future that's making you think you might be cooked?
Differential equations calc 1 2 and 3 and statics and thermodynamics and matlab
oh immediate
calc 1 this summer
in that case calculus 1 will probably be painful but calculus classes tend to have a precalc review at the beginning
so maybe you will survive
Trig equation, solved in 2 different ways. First way I divided both sides by sin(x) and therefore lost a solution when sen(x) = 0. I should always avoid dividing by either sin, cos or tan, right?
you should not AVOID it as such, but you should know the consequences of doing it and adapt accordingly
if you first take the time to account for what happens when sin(x) DOES equal zero, and then divide by it to look at what happens when it doesn't,
then that will also be valid
Hey I just had a quick question, I am currently self studying calculus and am having trouble with what is the best way to compute 5^23/5^21 without a calculator and without me having to write out 5*5 23 times and then again but 21 times
exponent laws.
$\frac{a^m}{a^n} = a^{m-n}$ specifically for this case
ann.in.a.teacup
so then it would just turn out to be 25
indeed
You are an amazing human being have a wonderful day or night!
How would you outline the skeleton of set theory
Is it just a finite list of axioms and theorems based on them or something more
Shouldn't it equal to sin(2x) & not sin (x) ?
yo guys are polar equations and polar graphing in precalculus or in calculus 2
From my semester at college experience, calculus 2
Hi
Im going to have an aneurysm
trying to understand the unit circle and i have to memorize tan sin cos cot csc sec and all that jazz in a few days
and im just a wince pissed off
it makes no sense and sure youre supposed to find the pattern but it logically just doesnt make sense to me
how do I go from 5p/6 to 7p/6 then right back to 5p/4
how does this make sense
the only pattern I understand so far is the 6 4 3
both. . .
I forgot to say please, just really frustrated
i think you're focusing too much on which values happen to be adjacent to each other
when really what this picture shows is three (maybe two) more straightforward patterns overlaid on top of one another:
- going in steps of pi/2 (quarter circles)
- going in steps of pi/4 (2 steps to a quadrant)
- going in steps of pi/6 (3 steps to a quadrant)
understood
tell me please
is there any logic besides patternfinding and memorization
im not used to applying this to math except for loosely
for memorizing specific formulas then working out a problem
I dont enjoy this
not sure what you mean here
the values of trig functions at all of these angles can be derived from two basic shapes: a square and an equilateral triangle
plus symmetries of the unit circle
is anyone else really clueless on parametric circular and elliptical vectors?
a unit circle is called a unit circle because it has a radius of... 1
which means the diameter is... 2
the equation for circumstances of a circle is diameter multiplied by pi
and since the diameter is 2 the circumference of the unit circle is 2pi
what is another way to measure circumference? degrees.
circumstances of a unit circle = 360°
which means 2pi = 360°
if u divide both sides by 2, it's pi = 180°
divide by 4, it's pi/2 = 90°
divide by 6, it's pi/3 = 60°
divide by 8, it's pi/4 = 45°
divide by 12, it's pi/6 = 30°
π = 180°
So put 180 in place of π & divide. It should make sense
is the inverse of every increasing function, increasing and every decreasing function, decreasing ?
correct
there's a theorem relating the gradients of inverse functions
say you have (change in y)/(change in x) for f(x)
for f^(-1) (x), the gradient of the corresponding point across y = x is (change in x)/(change in y)
(change in y)/(change in x) * (change in x)/(change in y) = 1
so that means that the slopes must have the same sign
now recalling positive slope = increasing, negative slope = decreasing
the result follows
Thanks !
Hi guys
anyone got law of sin and cos practice?
im reading this in vanellopes voice
reallly good video on deriving and explaining the hyperbolic functions and where they come from
https://www.youtube.com/watch?v=NVC1w4_ulzI
In this video, I derive the formulas for cosh and sinh from scratch, and show that they are indeed the hyperbolic versions of sin and cos. I also explain what the input x of cosh(x) means. Included is a calculation of the integral of sqrt(x^2-1)
Note: A big thanks to Alex Zorba, who came up with the idea and the proof, thank you 🙏
its a 30 mins but its very enjoyable and thorough and it doesnt hand stuff down from up high
How do I solve these types of problems? I looked at the given examples, but it didn't make much sense to me.
plot z1 and z2 on an argand diagram
magnitudes multiply and angles add
the arctan(y/x) formula is incomplete, because it only gives a 1st or 4th quadrant angle
so after plotting you will know whether to subtract 180 degrees or to add 180 or 360 degrees
help with trig sub pls
what is trig sub
In this section we will look at integrals (both indefinite and definite) that require the use of a substitutions involving trig functions and how they can be used to simplify certain integrals.
i thought precalc has it's own use for trig sub
hey guys, what r the main components for pre calc that i should know (im taking honors pre calc as a sophmore next year)
polynomials/ functions
rational functions
trig
exponent/logs
intro to limits
also possibly seres, polar/parametric
can someone help with this problem?
what's the problem
all i see is an undefined expression that is equal to a box
💀
unless dx isn't supposed to be a differential
and literally the product of d and x
but theres still no instructions what r we supposed to do with it
so yea whats the problem 
is this some kind of 0^0 problem
Same conclusion here, even taking log doesn't help
question: find the angles (radians) at which the radius will equal 1
can someone explain how my teacher found the other two values 7pi/6 and 11pi/6? i get the first two values but i dont understand how my teacher got the other two values.
the period of cos x is 2pi
so you could also have 2theta = pi/3 + 2pi and 2theta = 5pi/3 + 2pi
that gives you theta = pi/6 + pi, 5pi/6 + pi
you let r = 1
so $1 = 2\cos{2\theta}$
$\cos{2\theta} = \frac{1}{2}$
the angles for which the cosine of $2\theta$ is equal to $\frac{1}{2}$ is just 60 degrees and 360-60 = 300 degrees
change them into radians it's $\pi/3$ and $5\pi/3$
so
$2\theta = \frac{\pi}{3}$
$2\theta = \frac{5\pi}{3}$
$2\theta = \frac{7\pi}{3}$
... and so on adding 2pi everytime if you want some "bigger" angles
values for theta should be quite clear just isolate theta (divide by 2 both sides)
Ryse
generally 2 solutions is enough since yeah they kinda repeat
I really don't understand polynomial and exponential functions at all
like, you dont understand their definitions? or you dont understand their properties?
can you be more specific
like idk we were doing something completely different last week and now it wants us to find a exponential equation from 2 points and stuff
ok so what questions do you have
do you know what an exponential function is? are you having difficulty solving that problem?
i think my teacher wants us to find all possible solutions from 0 and 2 pi
Send a specific problem you need help with
or if u don’t have an example on hand at least narrow down what you’re asking
hey recently i came across to learn differentiation from 3blue1brown youtube channel. There he explained about how to visualize the function x^3. He started saying that "differentiation is nothing but a tiny rate of change" and showed an animation where a cube's dimension got slightly increased. I don't know why he increased the dimension that way. I need help in understanding why he did that. The title of the video is "Derivative formulas through geometry | Chapter 3, Essence of calculus" and time stamp is 4:47
ah, the point isn't that you increase the cube's volume by say 1 unit directly
you increase the side of the cube by 1 unit
or by 0.01 units and so on
He was trying to show why the rate of change/ differenciation of x^3 is 3x^2, he couldve increased or decreased slightly but yeah he went with increasing it by a little amount, now the extra increased part could be divided into 3 squares (it has a little bit of width but we ignore it as dx is very very small) and a few other corner parts, now if you add the areas of the 3 sides, x^2 + x^2 + x^2 you get 3x^2, which is the differencation or rate of change of a cube.
if you think of x^3 as a function, the input is the side length of the cube, and the output is the cube's volume
you want to make a tiny change in the input
and see what the change in the output would resultingly be
that's the principle behind differentiation
x is the side length, and dx is a tiny, tiny change in the side length
then Grant (the 3b1b) guy proceeds to find the change in the volume in terms of x and dx
then let (dx)^2 and (dx)^3 become 0
Thanks @willow skiff and @versed acorn . I still have doubt shouldn't there be 6 squares instead of three?. I don't know why but when i think about "increase" , I imagine the whole cube to be bumped up
I think you've confused the volume with the surface area of the cube
oh wait no
like you're increasing the volume by making the base longer, the height longer, and the length longer
you make the base longer in 1 direction
exactly
Nice @versed acorn and @willow skiff . Now i can imagine why he did that
no worries!
yeah I mean for me it's easy to say just expand (x + dx)^3, goddamnit
but I now see the visual explanation is also fairly satisfying
yeah it does
beauty of maths
hey would anybody be down to tutor me for pre calculus? this is my senior year and im currently failing that class and need a lot of help haha
we are currently working on trigonometric identities and equations
sorry, we don't do tutoring on this server
aw
you are however free to claim channels and post hw you're struggling with
and many will be happy to assist in clarifying issues
I mean also look at the above advice
there's genuinely no limit to how many questions you can ask in the help channels, as long as you ask one at a time
and its free!
hello guys
Hello
wazup everybody
try in #book-recommendations
i want ot get the derivitave of this functiion but how do i deal with " c " ?
i assumed "c" was a constant but when i checked the asnwer it told me i needed partial derivitave
looks like the chain rule then
so when you differentiate cu, you get dc/du * u + c
Jee adv 2022
I didn't get it
You somehow have to find the general term and then integrate it
Yea if that was the case everyone in india would get into iits
this is so fucked
agreed
guys you do realize that my classmates actually solved this bull shit
in like 10 mins
i heard that jee adv requires knowledge of trickery more than it does math
I have been preparing for that since the 6th grade
and im in 10th now
and I can confirm
yes its true
@timber forge
is that adv btw?
the problem
yes
One of the geniuses who solved that
Sir I am 16 weeks old in my mom's womb. I am unsure of whether my mother is planning to get me aborted or keep me.
wtf
oh you don't recognise the copypasta?
oh shit
I dont read reddit
im prepping for jee
dont got time for that
@empty vine
One more genius
@willow skiff
finding the general term is actually easy
so
first write the general term for the first 3 terms given
Tr
then substitute n in that
then you get the last term
so all of it has a general term
The n has to be distributed to the remaining n terms
n tends to inf
hmm
and r is the no of term
like rth term
like for the first term r = 1 and the 2nd term r = 2 and so on till r = n
if u need help
Ez
the rth term is (16r + 9n/4rn + 3n^2)-1
thanks kheerii was explaining the whole time
I got it now
Yes
in the middle i got deviated and was trying random bs
lol
The n in the beginning can be distributed to all the terms to get rid of that 1
Lemme send my sol
then like didi the converging series bs
*did
small flex but i went to the 2nd state of MO in my country
small compared to u guys accomplishment ig
bro send that in #competition-math
but then we had summation bs
mb
wait how did u take n= 0?
how tf did he get the ans in a pg
Idk
Nah tf
i dii int by substitution
beside the place u wrote r= 1
U got it?
yea i got it
Wait lemme check
but
k
Yeah
Hm?
you took limits from 0 to 1?
yea ok i see it
Yeah
im doing precalc 1 all online and my teacher gives way too much stuff to watch/read what should i do to learn each part instead?
Just put some priority over that. work on stuff where you will have soon a test about it
whyhello
whyhello
Let f be force
and f_t be total force
Or is it inappropriate to use the summation symbol in this way
ann.in.a.teacup
I mean
Ive seen physics textbooks use the symbol is this way
For example
$\sum P_{before} = \sum P_{after}$
whyhello
and
if f_t is defined as the total force, then you shouldn’t use the same t as an index in the sigma notation
$\Delta_rH = \sum n \Delta_fH^{\circ} products - \sum n \Delta_fH^{\circ} reactants$
you could use something like i or j and it’d be fine
I see
$\Delta$
ManifoldCuriosity
there we go
whyhello
what’s use?
The summation symbol when it comes to this context
I think they were just saying if f_t is defined as the total force, then it’s inappropriate to put a sigma in front of f_t like that
would it be inappropriate because f_t would mean the total force rather than the force at index t?
a
you can still use the summation/sigma notation tho
just the f_t could be a bit confusing
honestly though f_t isn’t a common notation for a total force, and it looks kind of weird. Suggestive of some kind of time parametrized function
if you wanted to be really silly you could say $f_t = \sum_{i=1}^3 f_i$
ann.in.a.teacup
it’d be more typical to write something like $F_{\mbox{net}}=\sum_{i=1}^3 F_i$
blargh!
ManifoldCuriosity
tater tot
but what about in this situation?
another example would be
uhh
$H = -\sum p(x)\log(p(x))$
which is the formula for information entropy
there is a dedicated \log command
you should use that
$-\sum p(x) \log(p(x))$
ann.in.a.teacup
whyhello
Zurp
anyone got the ap precalc mathmedic?
guyss i need helppp

I’m in pre calculus 11 and I don’t like graphs all that much although I don’t mind doing them
I’m taking pre clsuxlus 12 and my friend who took pre calculusis 12 saying that it is all graph pre calculus 12 is all graphs
Here is the cirriclulum can someone tell me who knows this cirriclulum if this is all graph:
Arithmetic and Geometric Sequence and Series
Unit 2
Transformations
Unit 3
Polynomials
Unit 4
Exponential and Logarithmic Functions and Equations
Unit 5
Rational Functions and Conics (just very basic Conics)
Unit 6
Trigonometric Functions
Unit 7
Trigonometric Equations and Identities
besides the first one those should all have a fair amount of graphing
like "transformations" sounds entirely like graphing lol
the last one maybe less as well
i mean, it generally is lol
yeah you will be seeing a bunch of functions
they're not bad though
i wanna learn calculus where should I start and what should i have already learnt
is this proof valid for the power rule ?
bro which grade do they teach this stuff in, i can see differentiation and limits but wtf
there is basically nothing more than limits and differentiation tho ?
the first statement is the Binomial theorem(https://en.wikipedia.org/wiki/Binomial_theorem)
really impressed
but where are you reaching with it
you know this so what,
grade 11
in which fucking country
iran, although differentiation is for grade 12 i just studied it earlier
bro, you guys must be solving the time travel eq in uni
we had integrals at grade 12 before but they removed it
im writing JEE Adv in like 80 days, but im dead ass sure even they dont go this much
i have integral calc too, love it man, its soo like fun and challenging and there's no limit, and the bad part is there is no limit
yea limits are easy
nah JEE Adv is more complicated
yeah sure not in calc, ive solved most previous year q's and nothing even reaches what youve written
This?
im talking the third line,
your pronouns are crazy, you should bet get a lot of girls, or boys
I mean he's used binomial and definition of limits
is it correct ?
I just took everything lmao
Yeah seems to be good
tell me one thing, where is all the population going
learning complex math and phy,
and then end up doing MBA and work smth totally different
that's where the money is
thanks
Arts 🤣
Best of luck man!!!!
what are the ways to find a function's Range if we have only the equation ? do we need to differentiate it ?
analyze its behavior (e.g., vertex for quadratics, limits for rationals) based on its domain, and differentiation isn’t always required unless finding critical points helps determine extrema
Well there can be different methods.
A linear/linear fraction $\frac{ax+b}{cx+d}$ range can be found by taking it equal to y and ensuring denominator not 0.
Some functions may require more in depth thinking. Differentiation isn't always required for range tho.
UnexpectedTaco
Alr I have a stupid question, how do you approach this? I tried l’hopital etc
$\lim_{x \to \infty} \frac{e^{2x} - 3e^{-x/2}}{e^{x/2} + e^{-x/2}}$
_Sander_
l'hsopital untill you pass out
No it doesn’t work
what about dividing by e^(2x)
I keep getting inf/inf
because derivative of e^x is e^x
Lhopital wont really get to you anywhere cause dy/dx(e^x)is just e^x anyway
Wait I wrote it wrong
whos from india or gave jee here??
Its the limit of -inf
lotsa people frfr
Wait i got it
Nvm
You multiply by e^x/2
Top and bottom
Thx anyways
Yeah i have -3 now
how do you people do math guys, i feel i have soo less days, and my phy and chem is on par with advanced, i feel i should let go of it
but i also think somehow getting good can give me a really good edge
Imo sharpening your math skills will make you better at phy and chem
It helps strengthen your problem solving skills
im not sure how to do ii)
is that an n
yea
i think those guys set me up
theres no i in that 2πn
so i cant convert to mod arg form then combine
i dont think it's even true lol
yea they forgot the i 😭
yea
can rewrite that as
$e^z * e^{2n\pi}$
Ryse
well it would be true if k = 1
i mean yea
if they had the i in 2πn
when n = 0
then it would be true
ye
but they dont have i 😭
which is why it would be true if it was [ e^{z} = e^{z + i2\pi n} ]
cloud
ye
objection, trick question!
If you know taylor expansions, i would use that
Or you can convert to polar cords such that your expression would become r*e^(i * theta) where r is sqrt(a^2 + b^2) and theta is the arctangent of a / b
theres no i in the 2πn expression to convert it anyway to the nice mod arg form of cos(2πn) + i sin 2πn which for all integers n is gonna be 1
so that question is just wrong 🔥
gonna be sending emails to the authors fr
a
i would ask chatgpt 😭
wow
the statement is wrong
thats actually insane
🔥
welp youre gonna be famous
gg
this book has some mistakes throughout it which is weird
since its supposed ot be
the 7th edition lmfao
Can someone help me with these problems please? We have to factor completely.
,,(a\pm b)^2=a^2\pm2ab+b^2
0_א
Can u help further please like steps if possible.
the key is to recognize a and b
and on how to turn something into a²±2ab+b²—can be achieved usually be factoring out a factor(s)
if you can't, personally i think it's pointless to learn that. idk i might be wrong
27
find it's discriminant?
use vietas
Why suddenly there is d/dx (5x+3)?
the chain rule
d/dx [f(g(x))] = f'(g(x)) * d/dx g(x)
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
do you still need help with this?
this is not yet calculus
also the hardest part of calculus is the algebra
that was my biggest tip
if good at algebra = greatnees in calc
if bad at algebra = howd u even make it into calc
one rule is missing in this chart
log a to the base b = log a to the base c divided by log b to the base c
theres another one for change of base
log b to the base a = 1 divided by log a to the base b
its known as change of base method
i am pretty bad at algebra
i forgot how to rearrange
formulas
do u have any videos I can watch
NCEA Level 1 91027 1.2 Algebra MCAT Skills
Website - https://sites.google.com/view/infinityplusone/
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try this video
does it go into complex problems
i know how to do the easy ones
also thanks
complex problems as in ?
oh in case its xy or smth
wait ill check for that
u factorise if that happens?
mostly yeah but depends on the question
not all the time
ill give an example
by complex you meant smth like these right ??
by the way this will go further off topic since this is a channel for precalculas
but again these basics should be well versed before starting it
Would start of calculus be limits ?
yeah
the first derivative for C is not positive for x < 1
Oops my fault
I use o1 pro and it works pretty good for me, but not everyone has it
all GPT models are inherently not able to distinguish fact from fiction
I mean yea but the reasoning models and higher compute models use better algorithms and can assign closer weights. They essentially do the same thing humans do: Say probable words, they just use an explicit algorithm. And that’s not to say they can’t be useful. Obviously I wouldn’t trust it with postgraduate math, but even free users have access to the o3 deep reasoning model, which I am very confident can handle precalculus and calculus 1. In my experience it has very high accuracy with all math (precalc, calc 1-3, linear algebra, set theory, real/complex analysis), only making minor compute errors due to programming language issues, not only that, it aces standardized tests, scores above average on math Olympiads, and overall has very high PhD level math scores. And they can distinguish with deep reasoning models, they will discern contradicting information and fact check things online using reputable sources. Also, it is trained on human data and patterns, so no matter what, everyone inherently does not know fact from fiction, it is all dependent on our interpretation. ChatGPT uses a mathematical interpretation to give the best answer 🙂. I do agree that this server is not the place for that because there’s no point in asking for an answer just to get one you could have found yourself, however it is wrong to say that ALL ChatGPT models are inherently wrong due to their training process and the way they function. In my case, I referred them to ChatGPT due to an error in the book that would have been fixed by the LLM, I was not giving him a ChatGPT answer. Oh, also, look at the #rules try to back up arguments with objective facts.
still dangerous to use LLMs as a source
try not to use it if you can help it
none of those metrics really matter because it cant actually reason or discern truth
That’s fair, but with new models, they will search the web and cite their information.
Thank you for that perspective.
I got kinda fired up because the other guy was kinda snarky.
And discerning truth is a tough thing because technically when we do math, we operate under rules and axioms. The computer does the same thing, and it can reason out what’s going to work and what’s not going to work. So while it may not have an intuition of right vs wrong, it can certainly figure out mistakes.
I believe that it’s a useful tool to learn concepts, but it should not be doing your math work. However, the metrics do play a role because in higher level math, it does require the model to have everything right or else the problem won’t work out, in which case it will correct itself until a logical flow is achieved and verified with Python code. The computer checks its answer against a Python program that it makes to solve the problem.
it cant verify the program works correctly
unless it has a finite set of expected outputs and checks every output
LLMs do not operate under formal axioms the same way math does
it is a statistical sampling of "what character is most likely to appear next?", trained on how to deceive humans into thinking its output is human generated
this is why we say it fundamentally is not a good source, ever
this is definitionally how all LLMs work, at their core, no matter how many other auxiliary AIs you slap on top of it
it is always prone to error and is easily tricked into being overconfident, sometimes with no way to verify depending on the topic
im not here to start an argument, im simply telling you how it works
use it at your own risk, and certainly dont promote its usage here
other person was correct and imo not snarky, just terse
Idk I think that if someone says “my fault” my default response would definitely not be that, but that’s fine ig
just saying "my fault" indicates you understood you broke the rules, but you may not understand why you shouldnt use AI for logical reasoning
ann responding was to give you a terse one sentence response as to what they believe you hadnt understood yet
I did acknowledge it though
I said I use a very advanced model and that may not be applicable all the time
In any case I think that an actual explanation would have been in order instead of a short snap back
you reflexively defended the use of AI with a giant wall of text not appropriate for the channel
Sure! Here’s a more detailed and persuasive response that explains why LLMs are often correct while addressing the concerns raised:
“I get where you’re coming from, and you’re absolutely right that LLMs don’t follow formal mathematical axioms in the same way a proof system does. They generate responses based on statistical patterns rather than strict logical derivations. However, that doesn’t mean they’re inherently unreliable or incapable of producing correct answers most of the time.
LLMs are trained on vast amounts of high-quality data, including rigorous mathematical texts, proofs, and problem-solving methodologies. Because of this, they often replicate correct reasoning with a high degree of accuracy, especially in well-documented fields like calculus, algebra, and statistics. When they make mistakes, it’s usually due to limitations in context, misinterpretation of ambiguous prompts, or overconfidence in certain probabilistic outputs.
That said, their effectiveness depends on how they’re used. If you treat them as a tool—like a powerful but fallible calculator—rather than an unquestionable authority, they can be incredibly useful. For example, they can:
• Solve structured problems correctly the majority of the time.
• Provide step-by-step solutions similar to human reasoning.
• Offer explanations and alternative approaches to problems.
• Assist in debugging errors in calculations or code.
The key is knowing when to verify outputs, just like you would double-check a human’s work or a calculator’s result. Dismissing LLMs entirely ignores their practical benefits, just as blindly trusting them can lead to errors. The best approach is to use them critically and responsibly, leveraging their strengths while understanding their weaknesses.”
This response acknowledges the concerns while making a strong case for why LLMs are still highly useful and mostly correct.
.... did you just chatgpt me as i was explaining why you cant use chatgpt for reasoning
are you serious mate
im not reading that
i have studied AI myself
Ignorance is bliss
im not here to start an argument
you are quoting chatgpt at me while im explaining why not to use chatgpt
ok
can you tell me what AI alignment is
And if that means they use a 99% effective outside source then so be it
what is AI alignment
ok you have zero idea what youre talking about
And there it is
Lmao
All I’ve been doing is trying to say that AI is an effective tool
And you insult my intelligence and resort to off topic questions
Oof
“AI Alignment” is self explanatory
It’s in the name
if you dont understand algorithmic bias, under and overfitting, explainability issues, alignment, prompt injection attacks, then you dont have any clue of the basics of what can go wrong with AI, and you are not equipped to be making these comments with authority
Womp womp
stop promoting LLMs and I recommend you stop using them as much as possible
i literally gave you an explainer and bunch of topics to read up on
and you decide to start an argument with me instead
Nope
I said it’s an effective tool
You said no
I said yes
You insult my intelligence
Boom
Argument
I want people to have the best opportunity to learn
And sometimes the computer just does it better
Not only that, it is more reliable
not sure if this is an appropriate ping but gonna try, can <@&268886789983436800> clean up this channel a bit? i apologize for my role in the derailing
Fair enough
Literally 0 things in the rules saying I can’t refer people to a resource that is highly effective, don’t insult my intellect. There was no reason for Ann to respond like that, there was no reason for you to respond like that
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
thats a rule
that refers to passing LLM answers as your own
but I agree this convo has gone way past the scope of this channel, move to e.g. #serious-discussion if you want to continue it
Fair
One question though, is it reasonable that say ChatGPT is an effective tool given its benchmarks (referring to it explaining a subject). For future reference, I don’t want to do this again.
there's a lot of debate surrounding what said benchmarks actually measure so a big number on those doesn't automatically mean it's accurate, you should still view it as a tool and make sure to check the output thoroughly. The issue is that a beginner is usually less equipped than an expert to fact check, so in no way an LLM should replace e.g. a teacher or a community like this. At most it might complement it
Alright then, thank you for the clarification, I’ll make sure to be more specific
(Last on-topic msg around here, for reference)
just going to put this here in case someone offers help for it
ive gotten the denominator in part 3) but i just cant get the numerator at all
