#precalculus
1 messages · Page 13 of 1
u might if ur dad is rich
it's good to aspire
or u are super talented
Idk about that, people who are 13 or less don't know differentiation ideally
chain rule i'd imagine
idts
hat I am get a double digit rank in jee advanced to even get accepted in mit
plus u need to bring in olympic medals
i think it is
You got a double digit rank in jee advanced?
you use chain rule when you're differentiating composite functions
I have more than double my age
medals
if you're trying to differentiate gf(x) then you'd set u to f(x) and y to g(u)
oh
I hope I become a single digit ranker
how much does one need for iit bombay computer science?
double digit
Because I'm a tech nerd, math nerd, science nerd, so, I love Computer Science
yeah
do u listen deftones?
ur bio
I don't even believe I'm getting in MIT
if I ever even going to
Nope, accredited institutions only
ya
you need US citizenship well
probably one of my favourite bands ngl
you know why
listened few of them before
can someone give me a precalc prob, im going to ap precalc next yr and i wanna see what its like
Why not just search up problems?
i did but i dont know which is beginning and which is harder
ok ty
is that rsm
lmao
13c3
so 13211
13x2x11
286
is it 286
@viscid thistle
hmm
is it a permutation..?
its um
286*6
so
1716
i think idk
lol ty
ty
ruh roh
is that ap?
damn it
im about to be a freshman
ty lol
alr gimme all the rsm
teamwork makes the dreamwork fr
idk
send me some
yes
like 5-10 problems
ill help u
mhm
ill try to do them
in dms
fr
anyone know types of cardinals?
as in the birds??
a true infinity that cannot be reached
alright
its useful for power scaling
yes dawg ill do like 5 problems 😭
also do you guys know what set theory is?
kinda
Cool i joined this server to understand such things as that, i want to scale goku's cosmology using mathematics
yk who goku is right
yes
yessir
The living world in db countains all sets of mathematics, including set theory and cardinals
sdbh zamasu 🤮
Is tangent the length of the hypotenuse on a triangle in a unit circle
it’s the ratio of the height of the triangle to the length of the triangle
frfr
think of its derivative
whats the derivative of e^x?
and for e^(x/2), we generally apply u-sub to x/2 and it follows from there
can somebody help me solve this partial derivative?
this is just a regular derivative
to see this $z' = 2\sin(x+2) = 2\sin(z+2)$ or $\pdv{z'}{z} = \pdv{z'}{x}$
ForJoke
derivative of a function is e^x. if we define the unknown function as c^x we can conclude that (c^x) * ln(c) = e^x. (ln(e) = 1) hence the unknown function is e^x it self.
right, wait a sec
ok what about now
can somebody help me solve this partial derivative?
technically this is 0
because 2sin(6) is a constant
and the derivative with respect to a number doesn't really make sense
unless you are saying that 2 is a symbol and not a number
ah, who cares about technicallity, how would I solve this algebreically, also 2* 4 is 8
Are you trying to find the derivative at 4?
no that would be zero you brought up a good point tho
derivative at 4 is not 0
that would be reverse chain rule
integration by substitution is like doing the chain rule but worse in every way
because you have to restate the integral in terms of u
and its sometimes extremely vague how you should do that
thats not what I meant but its whatever
sorry Im confused of what your question is
no its allright I have also formulated it wrong and mixed things up, but I finally understood my problem and managed to get a better grip on it
hey, how can I get help for precalculus?
by posting the question(s) you need help with
Yo is this correct what I have done here?
looks good
nice
idk, but I would have loved to study in sweden they appereantly have great education system
The math SAT is not too difficult. It is a standardized test that is designed to be balanced regarding the general population, so don't mistake it for the hardest math problems. That said, I do feel like the average US math curriculum for grades 1 to 12 is mediocre compared to math systems in certain other countries, although colleges are a different story.
There are many top colleges in the US, so completing a graduate course in the US is a decent option.
It depends what college tho
Yes, but I didn't want to say that because it doesn't hold for everyone. That's why I said "not too difficult".
Algebra 1 is sort of the introduction into higher-level math, so it isn't supposed to be very hard. I would say the difficulty begins with integration, but it's different for everyone.
difficulty is trig imo
I haven't taken integration yet but I've heard that a lot of people struggle with it.
I didn't struggle with trig but math is a strong subject for me.
So I can see how it could be difficult to wrap your head around.
should i take multivariable?
Idk, what grade are you in and what's the highest level of math you've taken so far?
im boutta be a freshman going into ap precalc
wbu
Then you could take mv calc in 11th grade if things go well for you
Or even 10th
that would be too hard for me imo
Ya you decide ig
I'm about to finish 8th grade and I've completed everything up to alg 2. I haven't taken precalc yet but I have experience with limits, derivatives, and other calc topics so I think I'll be fine.
No I just was about to say something and then changed my mind lol
Lol ya I talk like that
I think precalc will be quick for me so I might be able to unofficially take mv calc in 11th or 12th
At school precalc
precal next yr?
ap or normal
I might go for a math degree in college along with a cs degree or something
I did it
a few kids in my school did it too, calculus in general is actually easier than algebra in many respects
at least calculus 1, assuming conceptual parts of math are not something you struggle with
Plus the added advantage of taking calculus as an AP course in highschool is you get a whole year to digest the concepts and be able to work with them, rather than in university where you are only given half a year (or less depending on how semesters go) so in a lot of respects you will actually learn it better
that is, assuming you are being taught just as well in both cases
highly recommend you do it if you aren't struggling right now in mathematics, if anything use this discord. I certainly wish I had something like this going through school
Wdym unofficially
i think he means hes not sure
multivariable in tenth grade??
ye im taking 2 ap calcs
I meant that it's not counted by the school system when I skip levels after taking them outside of school, so in the school system I'm restricted to taking precalc next year.
Basically since the highest level of math I've taken in school is alg 2, I can't take calculus for example next year, I'm restricted to precalculus. Likewise, because I take one math course each year in school, even if I get to mv calculus early I still have to do the school prerequisites, which will take me 2 more years after precalc.
That's not what I meant.
hes not sure as in youre not sure if youre allowed to take it
whos the owner of this server
no no no haha calc 1
but multivariable is very similar to calc 1
the generalizations are very natural
except maybe stoke's and green's theorem
Ya calc 1 is totally doable in 10th, ik someone taking calc 1 in 8th.
What about calc 2? Is that also similar?
same
i take that junior
I take it junior as well, at the current rate
It's the first half of calculus 2
Can someone explain to me why if we take annual compount intrest with imaginary intrest rates the capital raises significantly after 8 years ie. We get spiral but if we have same intrest rate but we compound the intrest continiously (instead of annually) we get to a circle and dont make any profit in the end
Ya tbh idk if it's actually difficult or not but people have told me it is
Euler's method (for approximating solutions to differential equations) gets increasingly accurate as you decrease the unit step
<@&268886789983436800>
Mods are asleep I guess

They were
I mean they're still human, right?
Of course.
I don't blame them for anything
Sheesh, 3 minutes response time. Off with our heads!
More like 20 to me
Actually moderation is great here compared to some other servers I'm in. Let's appreciate it
Yeah overall it's great
I mean, I'm in a server with like, what, 50k members? And moderation is zero tbh.
The modping shows at :43 for me, logs clock the ban and cleanup at :46.
Well uh mods have a life too.
They aren't living just to moderate the server
So pretty much understandable even if it takes more than that.
they should be grown in vats to moderate
strongly disagree.
you'd be able to bioengineer them to be the perfect moderator
equation of circle: (x-a)^2 + (y-b)^2 = r^2
where the centre is (a,b) and the radius is r
Haha that might actually work!
This was regarding my ping 20 min earlier in #competition-math btw
is it always necessary to check the solution of radical equation ?
it is when you make non-equivalent transformations, yes
@summer ruin what do u mean by non-equivalent transformation?
applying functions which are not monotone
ln(x) > ln(y) if and only if x > y, provided x and y are positive numbers, meaning given the inequality x > y it is equivalent to stating ln(x) > ln(y), so it stating ln(x) > ln(y) implies that x > y
x > -5 and x^2 > 25 are not equivalent
same thing work for equations, the equation ln(x^2) = 1 and 2 * ln(x) = 1 are not equivalent because ln(x^2) is defined for all non-zero x, while 2 * ln(x) is defined only for positive x
the equation sqrt(x) = 5 - x is not equivalent to x = (5-x)^2
hi
i finished 10th rn
and i wanted to revise precal in summer
is there a certain way in which i should approach the topics under it
for example matrices first, and then idk
have you studies functions?
yes
what does full include
then you may study matrices but it doesn't come under pre calc
well there's a lot
till where have u studies?
basic graphs and all?
quadratic equations represented on graphs
finding roots
vertex form
and all that stuff
not sin, cos and tan graphs
though
our school didnt teach us trig function graphs
yeah
isnt that easy though
but there's more than that
oh
there are many properties
organic chemistry maybe
<@&268886789983436800>
Does anyone know where I can find a better explanation of the tangent and cotangents of sums section here? https://en.m.wikipedia.org/wiki/List_of_trigonometric_identities#Tangents_and_cotangents_of_sums
In trigonometry, trigonometric identities are equalities that involve trigonometric functions and are true for every value of the occurring variables for which both sides of the equality are defined. Geometrically, these are identities involving certain functions of one or more angles. They are distinct from triangle identities, which are identi...
I'm looking for a source that gives a proof
umm...
i think you shoukd try ck12.org
i think youll find good info there under the precalc section and analytic trig
hope this helps
<@&286206848099549185>
black pen red pen
Do they have a section on angle sum identities when the sum is arbitrary and potentially infinite?
For the identities tan(sum_i=1^n)=(e1-e3+e5...)/(e0-e2+e4...)
?
A lot of the resources I find on this are aimed at just basic trig identities - I'm looking for something that covers the more the more complicated formulas I've referenced which use more advanced math
I can't really ask in the advanced channels since they don't have a channel for trig
advanced identities?
In the general angle sum section
There's a formula for sin angle sum involving infinite products
The ones for tangent and cotangent use elementary symmetric polynomials, etc.
But I didn't find any source explaining it online other than wikipedia
how do i do the volume of a curve around an axis out of the curve?
Depends on shape dawg. That could mean anything. Look into Paul’s notes. It’ll tell u how to do it and the difference between volumes of revolution (methods of disks, etc) as well as volumes described by multiple integrals
I'll see into it thanks
Why does lim x->infinity n choose x = k for some constant k plot an ellipse on the complex plane?
The phrasings "lim x -> infinity" and "for some constant x" don't look like they belong in the same thought.
Lmao
i should be familiar with radian conversions before starting inverse trigonometry right
are there any study group here
ideally switch to radians completely
ah
so just practice radian conversions then
do you have any conversion practice worksheets
there's nothing to practice though, π = 180°, rest of the angles can be obtained by division
if the question involves angles which are not part of the standard trig table then the question isn't supposed to be solved analytically in the first place
and calculator doesn't really care which angle you use - in radians or degrees, as long as you use it correctly
so only the angles pi/6, pi/4, pi/2, pi and so on matter
Why is a invertible function and it's inverse always symmetric about the line y = x , also can we make a reflection of a function about the generalized y = mx+c line , and does it have like some general condition to exist (just like how the inverse of a function exist iff fof⁻¹ = I and f⁻¹of = I (this condtition is for reflection about the line y=x )) ?
you cant really solve any problem if you dont know how either radians or degrees converts to coordinates
standard trig table?
ive never heard of that 😢
what the...
i really need a baseline from where i should start learning
someone told me to do inverse trig before doing differentiation and i needed radians before inverse trig
now im dying
It is symmetric on the line y=x because the property of an inverse function is that for any output y it gives back the original value x wich is basically like swapping y and x axes. About the second question im not sure
Depending on how much time you have (i.e. are you writing a test in a week or do you learn it just for fun and have years). If you dont have much time just start with differentiation and when you encounter some problems look them up and learn those. If you have alot of time or find yourself lost/missing alot of basics check if you can comfortably do the following:
- linear and quadratic functions, solving equations, Pythagorean Theorem, Quadratic Formula, polynomials in general etc.
- Trigonometric functions like cos(x),sin(x),tan(x) as well as exponentional functions etc.
- you might as well do the inverse functions too like log(x), arccos(x) etc.
You dont necessarily need radians for those but it makes everything easier. - Limits. Limits are commonly used to define differentiation and are thus useful if you want to understand whats going on.
i just finished 10th and im in vacations
for like 2 months
From the four point i mentioned, at what point are you currently?
@lunar copper
i would say
im done with the second one
but i have to strengthen them
and also
i havent done any polynomials
only problems with a degree of 2
degree of 2 are also polynomials, polynomial is just the general term
i see
But if you study them a bit you will soon realise that if you understand linear and quadratic functions you will also soon understand any polynomial (the only thing that really changes alot is how hard it is to find the zeros of the function)
quadatics is easy
you can just
complete the middle term
or use formula
i saw one of those fun polynomial videos where factorizing increases with difficulty based on the degree
and from 2 to 3looked like a huge jump
ive done logs but i havent really completely done exponential problems
ive only learnt substituting x values to find y values for exponential functions
For quadratics you have the quadratic formula, wich is pretty simple. For degree 3 and 4 there also exists a formula, although never taught/used in school because it is too long. Any polynomial above degree 4 doesnt have a general solution only using addition, subtraction, multiplication, division and roots
@lunar copper you should probably either do exponentials, polynomials or, if you want to, start with limits and the concept of differentiation and seing whats missing like that. Introductory Videos about limits etc. often stick to simple functions that you already know so you should be able to follow those. Also that approach is more fun in my oppinion.
sorry i fell asleep
ok i'll just revise exponential and polynomials
also should i learn factorizing a cubic equation
No. In case you need to do that just find one zero of the function through trial and error and factor it out to get a quadratic.
i hate factorising cubics
you have to try one by one
But idk how those scientist calculate cubic when the answer is disgusting
They use advance methods like newton rampson etc
i wouldnt call newton-raphson advanced by any means
and even then it wont get you the exact algebraic factorised form
insert cubic formula
yes easily
Understanding the definition and motivation for radians and the relationship between radians and degrees
Practice this lesson yourself on KhanAcademy.org right now:
https://www.khanacademy.org/math/trigonometry/unit-circle-trig-func/radians_tutorial/e/radians-on-the-unit-circle?utm_source=YT&utm_medium=Desc&utm_campaign=Trigonometry
Watch the...
oh you might've meant cubic formula
then maybe not
not because its particularly advanced just because it's very lengthy and a bit messy
and it's generally easier to just factorise at hs level
how to synthetic division when dividing by polynomial degree greater than 1
like dividing by a quadratic for ex
can't you just do the same thing
wait i don't think that works
what if you factorise it then divide by it's factors
also why have i never heard of synthetic division
Pls help I don't understand stand integration
yeah thats what I tried but In not sure where to go from when I end up with some extra remainer part (1/x-7 for example)
Area under curve
why is an inverse function its reflection about y=x?
I think Grant Sanderson goes through it on the way to the quintic : https://www.youtube.com/watch?v=aaW30_f2on0&t=5135s&ab_channel=TimothyNguyen i also prefer his approach of merging completing the square and s&p over the quadratic formula
Grant Sanderson is a mathematician who is the author of the YouTube channel “3Blue1Brown”, viewed by millions for its beautiful blend of visual animation and mathematical pedagogy. His channel covers a wide range of mathematical topics, which to name a few include calculus, quaternions, epidemic modeling, and artificial neural networks. Grant re...
Given a function y=f(x). x associates an x vaule with an corresponding y vaule which is determined by the rule of the function. An inverse function of y=f(x) “undoes” this rule. Such that f^-1(f(x)) =x. The reason it reflects across the x=y access is because you are essentially changing the dependent into the independent
Any tips for linear algebra? specifically proving a basis of R³
You'll probably want the #linear-algebra channel. (But be a bit more specific about what you need to do when you ask there).
It’s derivatives
Synthetic long division is weird
Just use long division
It’s parts of calculus so I think you should ask somewhere else
What is an "instantaneous rate of change" when change happens across time?
Help fund future projects: https://www.patreon.com/3blue1brown
This video was supported in part by Art of Problem Solving: https://aops.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Special thanks to these supporters: http://3b...
This is a good video though
Guys Im in 8th and I just started learning calculus. Any tips or video guides to help me?
i like dis
dis a good
is it for beginners
the derivative a the fuction
yeee
thanks!!!
or like the gradient of the line that is tangent at that point if that makes sense
Hello?
hello, does anyone know any precalculus concepts that are much easier or faster if they were to be done with calculus
even if i would never use it, I'm curious how?
i don't even know how it works
Can anyone explain why my book says that the function f(x)=3(-1/2(x-1))^2+2 has a horizontal stretch of 2?
if K=-1/2 wouldn't it just be the value of k?
There is no explanation, it just is a 2 for some reason and I am not sure why.
well the whole point of precalculus is to get ready for calculus so i don't think there is any
triangle inequality
since PF1F2 is a triangle, the sum of any two sides must be less than the 3rd side
distance between P and F1
this notation is more often used for a "metric"
although metrics are analogous to distances
the "standard" metric is the distance we are all familiar with
read LADR
in short, to prove a basis of R^3, you must prove it spans R^3, and that it is linearly independnt
Bascially: Prove some $x \in \mathbb{R}^3$ is in the span of the potential basis, and vice versa, and also that it is linearly independent, or that there is only one linear combination of the potential basi that equals the 0 vector.
amukh1
:D ah wrong channel shoot sorry
nah friedburg better as an intro
I wouldn’t know, I only have ladr
anyone know a good alg2 midterm practice final
I currently have an 89.2% in the class and I need to ace this last test to end with an A
anyone know any videos or books that explain calculus to someone whos never done it before
what part are you looking for?
quick q does sinx-cosx have a specific value or..
Hi how would you solve this?
is anyone interested in checking my work for my midterm prep packet? it’s 9 pages lol just as much as you would want to do
<@&268886789983436800>
sure yea hollup i’ll dm u
sorry i forgot😭😭
gimme literally one second
Yea so as much as your willing to check
and i have several days till i need to hand the thing in too so whatevs
oh it’s all good homie thanks for trying
anyone else that wants to look at my work feel free to tell me the numbers i got wrong

third page!!
check your qudratic equation
i think it should be 9+16 under the radical
fourth page top a) check the range. it’s a parabola so it won’t be what you put
fifth image -> check your solution to the top right problem. specifically the orignal function’s domain and range
fifth image again at the very bottom. make sure you remember the formula is:
f(x)=a(x-h)^2 +k
you seem to have made the 7 into a -7 by using the logic for inside the parenthesis. remember -> this one follows the “true” sign, not the opposite sign
also - you switched you domain and range here.
alright i’m stopping at the seventh page. hope this helped
thanks homie
What does this mean can anybody explain in a simpler language
,rccw
absolute maximum/minimum value is unique, but points at which it is achieved are not unique
"Essential" in the last sentence is a rather strange word choice.
And it seems confusing that is speaks about "maximum and minimum values" in the first sentence and "absolute maximum or absolute minimum values" in the second -- but I can't imagine any distinction it's trying to make between those two phrasings.
I guess they mean local max/min vs global max/min
Yeah, but that can't be it because local max/min are definitely not unique.
Yeah idk what the difference is then
<@&268886789983436800>
(Wonderful, autodelete is glitching again).
Why is this the channel where moderators are always pinned
observer bias

Guys change the first letter of "Sigma" to L what you get?
a <@&268886789983436800> ping
?
This isn't the channel for that snexky
Ok sorry apologies
might be a little dumb but im doing logarithims and since they are inverses of an exponential function im thinking
a^x = y
set a = 3
x = 2
y = 9
3^2 = 9
since logarithims are inverses we flip x and y but then we get 3^9 = 2??
and even if we solve for y i still end up getting
y = loga(x) or 9 = log3(2)
so 3^2 = 9 yeah
logarithm is the inverse of exponential
since 2 is x and 9 is y we flip them when finding inverse right
logarithm is just like saying
base to the what equals this number inside
so log 3(9) would be saying
3 to the what equals 9
so what is the answer?
2
wouldnt the format be x = loga(y) then?
does that make sense yeah?
what is x, a and y?
im on stewarts precalc textbook and its giving me
y = loga(x) which is where my confusion is stemming from
ah maybe you misread the things?
yep
to find x you need to do log a on both sides
log a (a^x) = log a (y)
log a (a^x) = x
x = log a (y)
nani???
what is going on here?
Yeah im like
maybe it is i making the mistake somewhere?
It looks correct
ill just stick with x = log a (y)
really confused as to why they have it reversed though
wait hold on
x = log a (y)
so log a (y) means that a to the what = y
to the what is x
so a^x = y
we already said that tho
yeah no they seem slightly off
Any ideas?
?
like any ideas on how they got it or do i stick with this^
aight let me write it down real quick
they got this wrong then
i can
It’s too complex 🫤
Even if it's too complex I like complex situations in maps
Maths
the inverse of a^x is loga(x) because loga(a^x) = x
(definition of inverse fuctions) if that's your question
but the original function and the inverse "swap" their domain and range, so if inverse of f is g: Df = Rg and Rf = Dg
Nevemlaci
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
Nevemlaci
@warm patio
Give me the integral general rule
I was doing a play on words 
Lol your tricky
@Mode
<@&268886789983436800>
Finnaly he got banned
Does anyone know a good pre-calc (e)book?
How do I set up the equation for alk?
for alk i guess u have to use 24000=8000*(1.17)^x
then x*12 to get the number of years when the city of Alk's population get triples
which also means that city of Bems population doubles in every (x*12) years
hi i just started learning about derivatives and came across this function in the "essence of calculus" series
the video said that he gave this function to the computer to look at many times between 0 and 10, and compute the distance function given "s(t)+dt", minus the value of this function t"
i didn't necessarily understand what he meant in this phase of the video
What is an "instantaneous rate of change" when change happens across time?
Help fund future projects: https://www.patreon.com/3blue1brown
This video was supported in part by Art of Problem Solving: https://aops.com/3blue1brown
An equally valuable form of support is to simply share some of the videos.
Special thanks to these supporters: http://3b...
this was the video at 6:30 if anyone is curious
he said compute s(t+dt) - s(t) for every point t and fixed dt
s(t+dt) - s(t) is the function for the distance time graph?
he later adds he divided the difference by dt
all the possible values you can input into a function to get a real number output
so s(t+dt) - s(t) /dt is the function for the distance time graph in the video?
sure, but it's a function of dt
wha..
dt is an infinitely small change in time right
how can it have a function
im sorry if i sound dumb i dont really like functions
because the set of all values of t is already predetermined, its' some segment [a;b]
.
if you change dt the graph that you see will change
it's finitely small, he says he chose dt to be 0.01
Does anyone know if this working out is correct for this question?
If not, can you please write a step by step working so I can better understand?
@stiff nebula There are somethings that are not clear, for example when you take the u substitution (correct step), the t^2 dt is transformed into du so you don't need the t^2. Also recall that coefficients can be moved outside of the integral sign
Is this really precalculus 
In Precalc, never seen that
LOL this is spesh level
?
specialist math is a math subject for the australian curriculum
Oh
i have this formula on my formula sheet
Because it’s not precalc lol
It’s calc 2
Dk why they’re asking in precalc channel tho
all you have to do is compute product AB and solve a couple of equations
that's the point
why not just write general B
b_11, b_12, ...
maybe you should be open minded and actually try my suggestion
a matrix B with entries b_11, b_12 and so on
the rest is just solving 4 equations for entries of B
(This belongs in #linear-algebra, by the way).
it would be the derivative of the distance time graph
heh
Given x^2>=4/m^2, find the minimum value of x
Where is the calc channel
Is there any name for this "theorem"? I also don't rlly understand what it's saying
this theorem has an analogue in differential equations and when sources “use it” they sometimes say they “used the method of undetermined coefficients” although i’ve never heard it named as a theorem in differential equations or difference equations
Not sure if there is a name for your theorem.
You may think about it like this; Someone long time ago have done different problems in same shape tons of time and they already know what the solution looks like. Then they will propose that that form of solution they have come up is a "general solution".
When it comes to proving what they have is THE general solution, mathematicians often like to apply some existence-and-uniqueness-theorem to justify themselves, but that’s another story.
Applying method of undetermined coefficients means, you have the table of "general solution to common particular problems" in your mind already, what you need is just the accompanied coefficients to complete your solution.
One more classical example is partial fraction. You know how the decomposition will go already. The only thing left is solving for the unknown constants A,B,C,…
Is that correct because my calculator gives me another answer
Or am I solving it wrong
they made a typo, they wrote cos but they used to correct ratio in their calculations
you shouldn't have followed what they've written
what's correct ratio?
consider the position of x and the 100m side relative to your angle
relative to the given angle,
is x the opposite, adjacent or hypotenuse
opposite
relative to the given angle,
is the 100m side the opposite, adjacent or hypotenuse
adjacent
yes,
oh
hence what's the trig function that relates those three things,
sin, cos or tan
Can someone confirm if I did this correctly?
Right, there doesn't immediately seem to be anything that indicates the scale of the diagram.
yea figures. I was stuck and the prior examples provided at least 2 pieces of info.
ty
www.parliament.uk says:
The clock dials, framed in cast iron and glazed with 312 separate pieces of opal glass, are 7m in diameter
4.2m long
The minute hands are made of copper sheet 4.2m long. They weigh 100kg, including counterweights, and travel a distance equalling 190 kilometres (120 miles) a year.
the 4.2 translates to about 13.75 feet which i guess i shouldve then rounded to 14
but thats not specified.
the rounding at least
Yes, but I think those 4.2 m must include the counterweight part sticking out behind the rotation axis.
gotcha.
The clock's gun metal hour hands and copper minute hands are 8.75 feet (2.7 m) and 14 feet (4.3 m) long respectively.
googling feet provides exact length
shouldve just googled it first time since they used a real world example
thanks
The numbers are internally consistent between 7m and 190 km:
$ calc 190000/365.2425/24/4
~5.41877428466475469494
$ calc 7*3.1415/4
5.497625
$
if i am solving for a missing quantity such as the angle sector given theta and the radius, should i convert the the theta value to radians if they gave it to me in degrees?
I am having a block regarding a question in my homework, here is the equation: e^(2x) - e^x - 132 = 0. I am quite confused as I have tried a few different ways of solving but its just not coming to me, any help would be appreciated. Does anyone have any suggestions on how to go about solving this?
Oh wait this may be the wrong channel, my bad
Take x = e^x
So your equation of
e^2x - e^x - 132 becomes
x^2 - x - 132 = 0
Solve the quadratic
x1 = 12, x2 = -11
e^x = 12
ln(12) = x = 2.485
We ignore x2 because you can't have a negative result to a logarithmic question
Thank you so much for the response. I was able to figure it out on my own but thank you again!
Oh nice good job
how do I find the exact value of the expression sin45 + cos30
Or use your calculator if your school allows you
how do I find cot (-pi/6) using reference angles
I am assuming it it in radians
cot(-pi/6) = cos(-pi/6)/sin(-pi/6) = -cos(pi/6)/sin(pi/6) = (-sqrt(3)/2)/(1/2)= -sqrt(3)
cos(-x) = cos(x) and sin(-x) = -sin(x)
because cos is an even function
and sin is an odd function
Hey! This may be the wrong chat but I don't know where to ask, I just got a new calculator and when trying it out I found that it says √2 = √2. How do I fix it?
Fixed it
yeah u prob accidentally put sqrt(2) and pressed ok
🤷
my casio calc doesnt look like that tho so idk
so, how do I rigorously prove that:
- if I substitute a limit's value into the function I'm taking a limit of, if the numerator of the function is nonzero and the denominator is 0, then the limit doesn't exist
- If I did the same, but now both numerator and denominators are 0, then the limit may be exist
?
it seems like you want to prove something else than what you're saying there
"if i substitute a limit value... ...then the limit doesn't exist", but first part already assumes it exists?
Ah right.
Hm...
How do I show that the limit won't exist unless I can factorise the numerator with a common multiple (which will show that it is a "removable discontinuity") tho? am I speaking sense here?
Are you talking about rational expressions only?
Because you cant just “factor out” a zero from an arbitrary function
Hello, I want to learn Calculus Can anyone help me?
Please read #❓how-to-get-help
Like resources?
Pre calc or calc
Pls explain L'Hospital's rule with example .
Ok guys so my friend is doing this double angle problem and I wanna know how the third solution isn't 7pi/6 (could possibly be 11pi/6) but why would quad 3 not be included?
pre
no just generally like formulas
are the solutions given by sin(theta) = 1/2 or sin(theta)= -1?
Yep I figured it out, I tried to do it the precalc way which I got stuck on but I used u-substitution and got -1 as a given solution hence I got 3pi/2 for my third measurement
<@&268886789983436800>
anyone know any precal video for beginners??
?
I am confused on part b. Here is my work and the solution from the back of the book
hm actually they say to express the real part
and jcos3t isnt real so my answer is correct
When given sin2(x-pi)
what is the horizontal shift of the function
is it pi to the right? or 2pi to the right
how hard is precalc?
depends on how adept you are w/ algebra, by a long shot
Im so tired of mathematicians putting calculus in everything
Wait
This is pre calculus channel
What have I been doing if not calculus
well, sorry to break it to you bud, a lot of math is calculus based. Even basic stuff like area of a circle to the value of pi came from calculus.
motion formulae are in that list
but please dont hate calculus. its a wonderfully useful tool with many real applications
I always get integration and differentiation mixed up
think of integration as just adding up a bunch of area of rectangles under the curve, with each rectangle being of infinitesimal(infinitely small) width, so you're "integrating" area together. differenciation is just the opposite
ok...
a level
ok that is year 11
in total
a levels are a high school program of 2 years
Year 1 of a level maths?
anyways, calculus is a huge component of math in the a levels
you're gonna need to get comfortable with it
yea but they're big modules
skip
and you also have differential equations
just leaned logarithms!!!!! calculus here I come
yay
whaddabout your trig 
What do you guys learn in precalculus?
algebra, functions, polynomials
exponents, logs
Can someone help me with this problem? I know that A^2 creates an identity matrix but I can't figure out the second part, "find another matrix (not I) with the same property."
just use a number analogy
if (a)^2 = 1, then what else could be squared to output 1?
A and A^-1 its the same
yeah i figured that out already, but i cant seem to form a general rule to create another matrix with the same property.
the exercise doesn't ask for that
how else am i supposed to find another matrix with the same property then?
A^-1=(Aadj)t/|A|
try this property
I suggested you one path
if you can't think of anything then trial and error is another completely valid way
and it doesn't even have to be of the same dimension, the question just asks for a matrix with property A^2 = I
i think thats just the question being worded poorly, my teacher doesnt find this textbook very good but its the one mandated by the school
no I think you're just overthinking it
what does the "Adj(A^t)" mean?
a lot of basic LA exercises are really just trial and error and that's normal, it tests how well you understand the basic relationships and how well you can construct the desired result if needed
like if you just consider this equation for some variable "a" that outputs 1 when squared, then you can fairly easily guess what other variable will square to 1
(not necessarily -1 or 1, this is an abstract equation)
A=A^-1=This
when i was trying to find a general rule for the problem i was able to get it nearly correct but the diagonal numbers weren't 1
This will be the property
general rule for matrices with this property is certainly not going to involve actual computation of A^2, it's deeper than that
and it's very likely to be far more than what's being asked
ok
sorry if i dont helped you
its fine
its hard to explain especially if I am not talking native language
whats your native language?
Spanish
thought so, your username gave off spanish vibes
its from a song
show me again
the adjugate of transposed matrix A
im struggling with precalc tests even though i can do the practice and hw, any advice
take a few past papers under test conditions to try identify the cause
how do i find real solutions to (4^x+2)(2-x)-6=0? (0,0.5 and 1 are easy to guess and they are the only solutions from the graph of it)
It's easier to guess them and then prove that they are the only ones, rather than trying to solve directly
f(x) = (4^x+2)(2-x)-6 is continuous, so you know when f(x) = 0 by checking where the sign changes (intermediate value theorem)
You already know that 0, 0.5 and 1 are such number, so you only need to know that it doesn't change sign before 0, between 0 and 0.5, between 0.5 and 1 and after 1
yeah i was trying to do exactly that, to show there are no more solutions..but trying to show, say, that it is always negative between 0 and 0.5 seems difficult
You can look at the derivative of the function to know when the function is increasing or decreasing, it would then be easy to check what it's inferior to on some intervals
If you really wanna suffer, you can learn about Newton's method or Lambert W
Does anyone have a summary of infinite and trigonometric limits?
how do i find the coordinates i should use when graphing y=6sin(2/3x) -3
first you need to know which interval you want to represent
having the sine function written, just quote values to build a graph the way you want, as long as the maximum value of y is 1 or -1
Can someone help me, how will I know. How much each point on the x-axis is when graphing transformations of sinusoid functions
Likely break under pressure
If two ticks is pi/3 then 1 tick must be pi/6
can i please get help w log functions
we have to try and create a graph from locator points n the equation
is there a certain equation we use to do this
y=log(x)
ok and
Study for 10 mins or so an hour before the test
Hello I need help with part b. I thought the answer was 19 but I got it wrong. Could someone look at my work for part b and tell me what I did wrong?
This is pre-calc compound interest formula. Nevermind I got the answer I just needed to add 19 to year 1995.
<@&268886789983436800>
evaluate f(2) first
how?
💀
are there enough info?
evalute f(2)
from the graph, f(2) = -2
now do g(f(2))
= g(-2)
ffrom the graph, its 1
hello guys
i am trying to solve this
and i just discovered the u substitution
but i still can t figure it out
u substitution isn't going to help you here
no
The standard approach for even powers of sine or cosine is to keep using trig identities to reduce the exponent
Maybe consider using
2cos^2(x) = 1 + cos 2x
cos(x)^4 = 3/8 + 1/2 cos(2x) + 1/8 cos(4x)
dont be too pedantic smh 🙄
Either u use reduction formulae or product to sum
alternatively, turn it into taylor series, integrate per term and leaev it as that
/s
or just do the physicist approach by and say cosx = 1
(turns out its not a bad approximation)
ok guys the job is done thanks you
this helped a lot
( i am maybe in the wrong channel sry i am new and i don t have acces to the calculus channel )
I think you need the undergrad tag, idk specifically tho
this work well too
(actually i dont even have
)
I only have 1 role lmao 
active
does anyone know how to find the inverse?
first u would do y=sqrt (x^2-1) then you would do x = sqrt (y^2-1) and then you would solve for y and that is ur inverse function
When you do the inverse write y as f^-1(x) =
yup at the end make sure you do that
At the end
i think that just means the x values have to be equal or greater than 1 cuz if its like 0 which is less than then the square root wouldnt be a real number
does making the function inverse do anything to that though?
f(x) fails the horizontal line test if the domain was R. The x>= 1 domain restriction makes sure that it suffices the horizontal line test and that f(x) is truly invertible
The range of f(x) will become the domain of f^-1 (x)
ohh ok got it thank you!
anyone know how this graph would look like? and how to find values of c?
do you still need help with this?
if yes:
are you able to graph y = x^2, y = 5.6-0.8x, and y=5 individually?
yea, i just dont know how to find the limits
well sketch the graph first
take the portion of y=x^2 that lies left of the line x=2
and the portion of y=5.6-0.8x that lies between 2 and 7
and the portion of y=5 that lies right of x=7
correct.
The Precalculus course covers complex numbers; composite functions; trigonometric functions; vectors; matrices; conic sections; and probability and combinatorics. It also has two optional units on series and limits and continuity. Khan Academy's Precalculus course is built to deliver a comprehensive, illuminating, engaging, and Common Core align...
Would just doing this be enough for Calc AB?
it should be adequate prep for enrolling in calc AB
the question never came
it was lost in translation
<@&268886789983436800>
If the focus is (0,-2) and the vertex is (0,0) then the equation of the parabola should be x^2 = -4ay, correct? Since the vertex is (0,0) and the focus is (0,-a) I thought it would have been x^2 = 8y because x^2 =-4(-2)y but it's marked incorrect by the program.
Any ideas?
since the foci is below the vertex, then i think it will be:
x^2=-8y
because the parabola is facing downwards
you're welcome 🙂

Fractions get annoying
Recently entered grade 10. i wanna know wether i should start studying this
how do i remove the he him tag? seems kinda cringe
#Channels and roles at the very top
thx
If u wanna do apcalc by senior year i’d do that but some schools don’t require to go up to the ap calc level. So just study it if ur major relies on it, like for example nursing doesnt need precalc so you’d study stats, but like lets say engineering, you’d def wanna take the calc route
thx for the info. any thing else to study for someone who wants to do chemistry?
I’m not rly sure at the top of my head, i’d say do research on your own but definitely calculus for chemistry, and probably statistics too.
alr
<@&268886789983436800>
What exactly about geometry do i need to know or would i be fine if i skipped geometry and went straight into algebra 2?
I'm currently taking pre-calculus in college. We are currently going over Conic sections. We already went over piecewise functions, complex zeros, properties of rational functions, polynomial and rational inequalities, exponential and logarithmic equations.
i use brilliant and it starts with conic sections
Nice! If you have any recommendations for resources then feel free to share because im self learning.
college board, always looking for a way to soak more money out of students
someone is paying college board the fees for when you take an AP class
if it's not you, it's your school district
or whatever other entity funds your school
my kids' high school pays the fees for AP students i think, but i'm not 100% on this tbh
of course
but the universal is that College Board expects to be paid
i also took precalc at a college and this is basically what we also did
for me it was mostly a repeat of algebra 2 but a little bit harder and some more work
shouldnt be too hard
for me i did algebra 2 and then geoemtry and we didnt really need to know much geometry for algebra 2 and i did fine in the class without knowing geometry
That's great! I'm glad you had a good foundation of algebra. I had good teachers in the past but I also had awful teachers that I wouldn't go to ask for help and so I became an autodidact in certain subjects.
Me
In your opinion, do you think I should just go over triangles then go on to trigonometry?
i mean ofc
geometry is triangles
thats like 90 percent of it
What about them specifically
A conic( cone shaped) are two intersecting cones using the formula for volume of a cone in 3 dimensions you can isolate specific slices
It poses an interesting question like when an circle becomes an ellipse becomes a quadratic which is useful in hyperbolic trigonometry, relativity, and many others
conics
so bad
they are a bunch of memorization ngl atleast for me
with the exception of parabolas and circles ig
I think conics are interesting. Let me talk about the ellipse.
If the foci are near the vertices the ellipse is more of an oval shape however if the foci is closer to the center its more of a circular shape. Some ellipses are more oval than others. Planets orbits are an ellipse shape. The Eccentricity of an ellipse describes the ovalness or the roundness of an ellipse. It measures the ovalness.
The sun is considered a foci
The planet orbit with more eccentricity is mercury.
If eccentricity is near zero then the ellipse is more circular but if its closer to 1 then its more oval.
I don't think it's about memorization. It's more about understanding. Math is the language of the universe.
There are vertical and horizontal ellipses each with their equation that is reversed.
the sun isn't just "considered" a focus (foci is the plural, and so "a foci" is agrammatical), it is at one of the foci, that's a basic consequence of orbital mechanics
sorry I meant to say is one of the foci
vertices is plural of vertex I get it
actually the sun orbits the center of mass the same as the planet, but because the sun is wildlyl more massive its orbit is very tiny
an eccentricity of 1 describes a parabolic orbit
and greater than 1 a hyperbolic orbit
some comets have orbits with eccentricity 1 or greater
they will make one pass and then depart forever
Google- The eccentricity of an ellipse is always less than one. The closer the eccentricity is to zero, the more circular the ellipse. The closer the eccentricity is to one, the more elongated the ellipse. Eccentricity e= c/a
yes, and an eccentricity of one describes a parabola
Oh I didn't know that I learn something new everyday
Im now learning about conics
Current unit
Thank you for the correction! Sun is at one of the foci, not that it is considered a focus. I understand now.
Are saying that some comets orbits hyperbolic meaning you only see it once and passes? That's pretty sad that people only get to see it once. Are there elliptical comets? I google search and it says that comets are highly elliptical. So, is the majority have elliptic orbits?



