#precalculus
1 messages ยท Page 53 of 1
opinion on hamsters?
where's this from? like which movie
๐
what did i say
his name is limey
I've been on my phone for 10 hours straight, I can feel my brain melting.
that is very cute
._.
is it your pet?
sleep, child
it looks like an anteater
named him after me btw
haha, cute
he probably does
I'll take it to 10 first.
and then die of brainrot
or
brain melt :>
mine is 8hrs
mine is 1.5 hours lol
mine is 0 hours :l
I've been simultaneously talking in 3 servers all along.
but to be fair i am on my computer more
zamnn is that even possible ๐ญ๐ญ
Heck!
sleep bruh 
it was 13 hours one day if it makes it better
not very proud
lies
guys we r supposed to talk about pre calculus remember?
I didn't even do my homework, I'm cooked ๐ญ
so tell me what is calculus?
limits, derivatives, integrals :>
d/dx and some
calc 1 at least
stuff
nice one good job
thanks :D
send sm questions rn
do i not get a "good job" as well
ew homework are u a kid (jk)
but not very tough plz
integral of sqrt(1/(x^2 + 1)) dx :>
tbh I am not kidding, i don't talk to kids
well its not very tough...if you know how to do it... ๐
Aren't you one?
I mean 11th grade is a kid no?
what is a kid tho ๐
we call it assignment 
Oooh heavy words.
what's homework?...
not what i meant ๐ญ
"deep inside we know" IT is "homework only"
what is IT

man is onto something or on something
can't tell
i hope u recover soon
Lol you've been on screen for a day imo
my question makes perfect sense wdym :l
i just woke up wdym ๐
oh...
you call homework "assignment"
it is "assignment"
coulda just
told me ๐

Lol I thought you were philosophising.
he doesn't know what homework is 
i got it but i cant type it here
do childrens also call it "assignment" where u live? @winter comet
us
Is 10 hours a day screentime really bad?
how much do u sleep
6 hours
thats enough
it's like ... really sad
yeah I mean sleep is enough but screen time is not
euler ๐ฃ๏ธ
yo from now on lets all of us share our screen time every night and tryna decrease it day by day
How much is yours btw?
ik its kinda cringe but its helpfull ig
I'm in, desperate in need of that.
it sure is
Doesn't seem cringe to me.
shhhhhhh do NOT ask
nice then lets do it
but where do we share it ?
In dms, is it only the two of us?
alright
i would love to but due to mathematical reasons i cannot
ok brodtha
Mathematical reasons.
You can install an app, I use it for studies too
For example it displays time spent like
done
sure
problem sets count as "homework" actually
but yeah we would just say oh I have work to do
subtle differences in the words we use for HS versus uni versus workplace probably
we call it homework, assignment, work, whatever lol
"i have work to do"
"i have to do homework"
"i have to do an assignment"
just depends on the context ๐
what was your process...
productive: 14 minutes ๐ฟ
can someone help me with my pre calc test review
Got a specific question ?
Yo
Putting x = tan(u)
i mean thats valid but you could also just remember that it's arctangent 
how do we solve question 26?
help
wtf
nah thats lowkey impressive
10 hours
I would expand all the sin2xs and sin3x and cos2x and cos3x
It seems like a lot of stuff wud cancel
Or factor
Hold up
It asks you to solve the equation
It says โcomplete the solution and justify your answersโ
If it asks you to justify, then the question is about what you did to solve it.
Just solve the equation and why
So I could pretty much say that the equation is solved bc both the answers arenโt more than 2, meaning both of them are valid answers
Tysm
Yea I know the derivative of arctan and tried smthng like that but it didnt go well
Yo is this watchu talking about ?
Is this the correct answer?
i do not think anything is
It is already solved
I could not have done the procedure but what I did was convert the sexadecimal degrees
Your handwriting is beautiful
Are there any other conditions here?
here, wouldn't the answer be same if the interval was open at 2pi?
yes
why u doing jee pyq though 
but then what difference does it make?
Thanks bruhh ๐ฟ
Me too
Next year is my paper ๐ญ๐ญ
basically
nothing, coz ur final answer lied very well within.thr given range
if suppose one of the answers was x= 2ฯ
then your answer would change for open interval and closed interval
however In this case, since x=0 and x= 2ฯ is not a solution to this answer, the answer therefore remains the same for both open and close interval
good luck man
okay, thank you.
When you plug in x=1 you get 1 = -1
Squaring both sides here is critical if one side is negative
Thank you so much omg
Iโm getting that bonus . @exotic barn I will make sure you see the heavenly gates. You have blessed my day .
Thank you, you too
๐ค๐ค
why?
Bro that's totally correct
No no no
U getting it totally incorrect
Wait lemme send u sol.
Btw what's the answer for this Q.?
Lemme try
Bro what's the ans?
-1/6
it's ok, it's tough haha
So what's the solution?
uhh this
No the solution like the whole process to this answer
I wanna know how to do this
dude I don't know the soln... If I know the soln, why did I ask here
Oh ok
Since sinx and tanx are โ x near zero
what's the best source to study inverse trigonometric functions? one that covers all things
the best way to learn anything is to invent it first and then compare with what's already known
Limits arenโt precalc, they are calc.
except when its, yk "precalc with limits"
like the extended reals ๐
There's not much to them imo, any class 12 math book should be fine. You got SL Loney?
i do not, but i will look it up. thank you.
Indian? If so the twelfth grade book is enough for it.
i get you, i just wanted to clear my concepts first
because trigonometry is a hard topic for me
Yeah trigonometry sucks
mhm! anyway, i am sorry; thank you for the recommendation
Lol why are you sorry?
it sounded like a stupid question
What sounded like a stupid question?
Btw if you are absolutely new to trig give trigonometry by I M Gelfand a try.
I M Gelfand was a great mathematician btw.
Hi guys How are you?
Good
Wbu bro?
Can soemoen please help me with this question
Is this polar coordinates ?
No
We do limits in precalc in my class ateast
Was it done for you
how do we solve tan(7x).tan(3x)=1?
Is mathematical induction precalculus?
Sure you could learn it in precalc
or in calc
or after it
There's no definitive comparison
Ooh ok, I am so lost in all of this tbh๐คฃ, what does induction even mean?
What do I need to know prior to mathematical induction?
If someone could like give me a roadmap, that would be awesome thank you if you do
what is happening here
have you watched this video?
https://www.youtube.com/watch?v=wblW_M_HVQ8
Courses on Khan Academy are always 100% free. Start practicingโand saving your progressโnow: https://www.khanacademy.org/math/algebra-home/alg-series-and-induction/alg-induction/v/proof-by-induction
Proving an expression for the sum of all positive integers up to and including n by induction
Watch the next lesson: https://www.khanacademy.org/...
You could learn proposition/predicate logic if you wanted to get a deeper understanding, but theres a bit you have to cover before you can get to induction
It looks like hes finding the range of values for theta on the LHS and range of values for r on the RHS
Write it as tan 7x = cot 3x.
Basically how many pairs of values of r and theta satisfy the given equation.
Then he rewrites rโด-2rยฒ+3 to show that it's greater than or equal to 2.
So he finds the intersection of the ranges of LHS and rhs to find the values.
An artificial question, as expected from coaching centres.
hey arjuna
yeah but what next? do we make it a quadratic equation?
The same old trick cot 3x = tan(90-3x)
11th?
Arjuna good though?
I see.
I'm asking because my parents bought the course yet I've never attended any class.
do not do that
if you have spent money on it then utilize it
you are going to learn something either way
But it's too lengthy though like 10 lectures of 2 hours each.
My bad
Oxford
oh
And ISI Bangalore
what grade are you in, if you do not mind me asking?
11th
well
like i said, rather than thinking about how lengthy the videos are, just start watching them
also
why did you buy the course? is it just not available on youtube?
I didn't buy it my parents did.
i mean sure not 100% but 70%, maybe?
Fair, thanks
what am I doing wrong here? it says the answer is npi+-(3pi/2)
What's the seventh line?
Sixth, my bad
sin^2x= (1/root2)^2?
why?
yeah sorry for that
Apparently you've done it all right.
npi+-theta
Like if it's npi ยฑ 3pi/2 how's that going to satisfy the equation.
I didn't though
2 would imply 1 = -1
I did it on paper I don't get 2npi - 90 as one answer.
i used the formula of cos(theta)=cos(alpha)
Isn't 45 deg added when it goes to the other side
yes but
it's +- alpha
so wouldn't it be + pi/2 and - pi/2?
i checked the solution online and the reason that they're not getting the second one is that they squared both sides
but do not we generally avoid that in trigonometry?
also what is wrong with my solution?
a - 45 = 2npi ยฑ pi/4 no?
yes
Yep, I agree that you'll get that
yeah sorry
what i was doing is
i was adding the angles first
if that makes sense
Then placing the plus or minus?
yeah
i thought it's in bracket or whatever
but yeah makes sense i am sorry that was really stupid
thank you!
Np
You can make sense of it by saying that cosec 2npi ain't defined. At least that's what I do
And that's not an option:)
fair enough
It's like those โ(xยฒ-x + 1) = 2x -1 algebraic equations where some solution doesn't make sense even though it's reached through an algebraically valid series of steps.
No you have an even more valid reason
Like you multiply both sides by sin x, if x is 2npi then that step wouldn't have been possible.
i mean ehhhh
what if the question asked about how many solutions does it have
let's say in period [0, 2pi]
It only has one because the other one doesn't make sense.
Ever seen a question like "solve x^2 - 1 = 1/x, x โ 0", it's somewhat like that, for the question to even make sense it must exclude the possibility of theta being 2npi.
You did functions? Like finding their domains etc?
yeah
Then you can sympathize.
i mean
like you can see, i am really weak at math
it's not what i am majoring in
so i do not see some stuff directly like others do
I can see that you are learning stuff pretty quickly.
You are actually, in my opinion at least.
Btw what's your major?
Cool
mhm!
I need to start learning programming too!
You'll probably get used to it quickly.
nein
Sure!
If you think I'm just saying that to make you feel good, I'm NOT!
also try to think about how actually stuff is working rather than focusing on syntax
It's actually the case that you can become really good at it if you shut yourself up in a room for a month. Like really good.
haha well i live with two other people, not happening lol
Fair, thanks, I'll ask for help if I run into problems.
plus it's my final year so there's a lot of projects and stuff
sure thing
$$\lim_{x \to -\infty}\frac{\sqrt[4]{x^4-1}}{\sqrt[3]{x^3+1}}$$
wolly5114
Like divide by x both the numerator and denominator?
You tried that @arctic meteor
Then bring the x into the root?
I see, it should be -1 but the way I suggested seems to say it's 1
the issue stems from x^4 not being a 1-to-1 function
so $\sqrt[4] {x^4} = |x|$ actually
south's secret twin brother
that means the sign will be positive/negative = negative
hopefully you get this reasoning
Fair
(similar to how the square root cannot give you a negative number, a 4th root is a square root applied twice, so same thing)
a 2n-th root is the same as the composition of a square root and an nth root
yes you can
it's not worth it in my opinion though
the way to justify it is to factor the numerator and denominator and then use the binomial approximation $(1 + x)^n \approx 1 + nx, x \to 0$
south's secret twin brother
how do we do #13?
and how do I conjugate the denominator?I'm clueless!
@willow skiff
the opposite would be $$\sqrt[3]{x^3-1}$$?
oh wait it's not even like x + 1 lmao, so it doesn't seem possible
so yeah textbook had a dumb idea that didn't work
it's factorable
I think
yeah $2c(2s - 1) - \sqrt{3} (2s - 1) = 0$
do i write 4sinxcosx as 2sin2x?
south's secret twin brother
wow
no
no worries!
Define f(x) = {x=0: -1, -x^2}, (-1 at 0 but -x^2 everywhere else), how can we know the limit of f at 0?
isn't the value of sin1 approximately 0? then why is the answer of 20 not (3)?
it's sin 1 radians they mean
no worries yeah trig uses radians by default
if they are using degrees they will say so
otherwise it's bad notation
makes sense
i already solve your questionnaire
that is sweet of you, but i got it already! thank you still ๐ธ
ok
I'm glad you're okay because you already have it.
Someone would like to support me on tik tok, I'm uploading math videos that maybe can help you.
i am not sure if this is a right server to advertise in
haha, fair enough
can you solve integrals?
yes
wolfram
No
no
Oh K
i dont think you are ready for this
is this you on your pfp
yes
i like your fit
I am the one in the photo
,av @lusty notch
Nah u female right?
pink diamond
i am men
I am the human race
women literally means us in Chinese
And man?
that's nan
Lol
Do you mean that I have traces of a woman?
what no
Oof
ok
Ok
im from Colombia brother
I see
what's u in 2.
why?
where cos3x.= u=3x.
cos u
these integrals are not hard but i dont get the u part
They are integral to Stewart's book
S cos(3x) dx = sin(3x)/3
then u = 9x/sin(3x)
you already solved the first one?
Computer math moment
bacc the sigma๐๐ค
Last one just split the fraction and use 1/e^x = e^(-x)
The first integral can be solved by separating into two, also applying the power rule and then using Barrow's rule.
Do you want an integral of me/oppailol?
bacc the sigma๐๐ค
Do you want me to solve it?
ya
??
lol
Is there a reason these two functions look eerily similar
it's telling you the substitution to use ๐
they're both related to probability distributions
oh you are right
near 0 they are very close together because the first two terms of their maclaurin series are 1 - x^2
i thought the . was a multiply symbol
3pi/5 = 5pi/5 - 2pi/5 = pi - 2pi/5
how do we solve question 9?
nahh bro like why did we do that and what was the sense of that step
we don't
i wish
to convert it into cos(2pi/5) for some reason which you must be aware of
oh
is this right ?
so the basic idea was to calculate tan theta and then substituting its value
yea
its alright
i wasn't attentive ๐ญ
lmao
lol this guy is llike my teacher ๐
please, you're studying math
yea yea im sorry
cos(pi-x) = -cos(x) and then -1 = e^(-i*pi) but i cant tell the context
$$\lim_{x \to +\infty}\frac{x^2}{e^x}$$ and $$\lim_{x \to +\infty}\frac{x^4}{e^x}$$
wolly5114
if both equal 0 is there any proof without differentiation/L'Hospital?
relative rates of growth/taylor series
Yes
that's not true, the denominator of the second one is e^(2x)
how do we solve question 14? what would be the first step?
Dedication ๐ซก
Write tan(P/2) and tan (Q/2) in terms of tanP and tan Q respectively
stupid question but how do I do that
Mb
brain is not braining
Let me check if that works
Ik ik
Since we know nothing about the lengths of the triangle , we should start thinking if there is any relation between the roots
Now it's given that the roots are tan(P/2) and tan (q/2)
hey
what if we multiply them? wasn't there a formula for
multiplication of roots?
or was it for something else
or add them for that matter
this probably makes no sense i am sorry
What is angle P + angle Q?
I don't think I'm thinking about the right answer
are you talking about the roots or?
No
We have a triangle PQR right?
I'm asking what the sum of angles P and Q is equal to
We already know that R is 90
?
Yes
right
Now,
Replace Q with 90-P and write down the sum of roots =-b/a and product of roots = c/a
You will be able see what to do after that
It's absolutely alright if you dont
do you think there's another approach to it? since we only want to prove one of the relationships given between a, b and c
a faster way, maybe?
Not sure
Maybe the fact TanP= tanQ would help you think of a different way
Lol,alright
Gn
why is the answer of #10 (3) not (2)?
Can anyone help, how would I graph a radical function when the x variable degree is higher than 1?
you can always start with a table of values
is there a way where I can just look at it and know? kinda like normal radical functions
this type of function is pretty common
try graphing and you should recognise something very nice
oh i see, you just plot the root of the constant value for both x and y
$$\lim_{x \to \pi}\frac{1}{1+cos(x)}-\frac{2}{sin^2(x)}$$
wolly5114
in the limit calculator it changes the angle from pi to t+pi
Is this how you solve it?
the answer is -1/2
just multiply the first one by 1-cos(x)
numerator and denominator
How to do division about this?
$$\lim_{x \to 0}\frac{sin^2(x)+2cos(x)-2}{(1-cos(x))sin^2(x)}$$
wolly5114
the answer is -1/2
how can i get that answer?
i tried the half angle formula and it didn't work
you can definitely try finding everything in terms of cos(x)
then sub in $u = \cos(x), u \to 1$
south's secret twin brother
how do we know which is the longest side in a triangle, if nothing is given?
wow
i would say atleast something will be given if the question asks u to find longest side

How does one go about doing 8 and 9?
In 8 how do I show that the error is numerically less than 0.0007 and in 9 how do I show that the error is numerically less than 1/6 xยฒ?
what did you get for the binomial expansion of $(1 + \alpha)^{-3}$?
south's secret twin brother
you need to use the term in $\alpha^2$
south's secret twin brother
Heck I forgot on which page I did that, I divided though.
Didn't use binomial expansion.
Wait.
If I'm not mistaken it's 1 - 3a + 6aยฒ - 10aยณ+...
Fair got it.
What about 9?
it's $(2 + 3x) 3^{-1} (1 + 4x/3)^{-1}$, then use the binomial expansion
south's secret twin brother
and expand up to the x^2 term again
I had tried division that didn't work, I wonder why, the book hasn't yet taught the binomial theorem.
Anyways thanks.
that is so weird
yes and we are using the fact that the maximum possible error is the next term
for when the next term is the largest in that domain
that's a fact from calculus
It's a pretty old book.
how do I proceed further? the options do not have a 'k' in them
huh wait what are a,b,c?
What's the question though?
hello guys
do u guys konw how to convert the gfe of an ellipse to the sfe?
it looks simple for me but im just confused how if someone can help me thank you
complete the square to get $4x^2 + (y^2 + 2y + 1) = 36$ and now you should be able to continue
south's secret twin brother
sides of the triangle
how do i know if its a perfect square and what do i complete the square with kinda
so $(y + k)^2 = y^2 + 2ky + k^2$
so we have $2ky = 2y$ and $k^2 = 1$ so.....
south's secret twin brother
This algebra video tutorial focuses on factoring perfect square trinomials. This video provides a formula that will help to do so.
How To Factor Trinomials: https://www.youtube.com/watch?v=-4jANGlJRSY
The Greatest Common Factor:
https://www.youtube.com/watch?v=ynefQgfxZBs
Differ...
honestly you need some revision; you should watch this
THANK YOU SO MUCH
whoever framed this question deserves to die.
i just realized that i need to revise the entirety of algebra
coz normally 3, 4, 5(A, B, C in this case)
are sides of a right triangle
nvm ig i m missing something
im gonna be fr w yall
i still dont get it ;-;
im starting to think my processing is t he problem
keep trying man
ah, got it. thank you ๐ธ
we all been there
damn
it's not. you got this!
what did u guys do to ui know overcome
im having lots of trouble with lots of numbers shown to me
start from scratch mate
start with basic linear equation and solving them
it will take time but it's way better than to develop a fear of numbers
ok ill try
I don't have an exact solution but you can let 2R = 1, where R is the circumradius
then using the extended law of sines, you just need to simplify $\sin 45 + \sin 75 + \sqrt{2} \sin 60$
south's secret twin brother
which does happen to be equal to 3 sin 75
hm
i didn't understand the significance of first half
u can just simplify the last expression u gave and find it to be equal to 3sin75
why did u put 2R= 1?
cause the options are all in terms of the sides
so by similarity, it doesn't affect the ratios between the sides
i have great news guys, i got the gist of ellipse, turns out i was just confused abt the terms buit the functions i get
:3
ty u guys
no worries!
i never learned the sine rule
but ig while calculating the area of triangle ABC
u took the side length as โ2 instead of 2โ2
?
(not sure if this is intentional or an error)
oh, yes
but it is still not equal to 4?
how do we know when to apply sine rule and when to apply cosine rule?
(not directed at you, limey)
huh how I think u r missing brackets
right
welcome
bump
choose based on what information is available to you
the rules give relations between sides / angle(s) in a triangle
note which pieces of info the rule uses and whether that info is present
got it, thank you
bro u speak like chadgpt
how do we solve this question? i tried simplifying it using sin(x-y) but it's not really working
what happened here
there is a common term of a^2 + b^2 for cos^2 x / 2 and sin^2 x / 2
if thats what you are asking
hi fudge
if it's given that the ratio of a, b and c is 4:5:6, does it mean that a:c is 4:6?
hello
i am doing okay, thank you. how are you doing?
hm?
yes
and yes u can also say a:c is 2:3 (more simplified)
i am just confused with the inverse thing, does the formula get applied in the same manner? i have not studied inverse trigonometric functions yet
formula where?
I do the procedure well, but from one moment to the next I get tangled and frustrated
i am not making sense, am i
i think this goes in #calculus
you can solve it?
no ig
unfortunately, no. i also think that #calculus would be a more appropriate place to ask this question, so you might want to head there.
i will come back to it later, thank you still
I have to go because I'm very sleepy
A brief description and guide on how to use me was sent to your DMs!
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context?
in complex numbers roots can return multiple values (square roots can return 2 values, cube roots can return 3 values, etc.) so the value you get out of it does depend on the order of evaluation
Is there any specific reasons for why we defined the latter as the correct order of evaluation?
if we take the square root of a real positive number, we would prefer to get a positive result. so if we have something like $\sqrt{49}$ we would not want to do [ \sqrt{49} = \sqrt{(-49)(-1)} \qeq \sqrt{-49}\sqrt{-1} = 7i \cdot i = -7 ] so we don't want to split up square roots which have the product of two negative numbers. this is essentially the same rule in reverse
cloud
Now I get it, thanks ๐ป
In an ellipse, the sum of the distances from any point on the ellipse to the two foci is constant and equals 10. If the distance between the two foci is 6, how to find the lengths of the major and minor axes of that ellipse?
length of major axis is equal to 10 as given
length of minor axis shoudl be sqrt(10^2-6^2)
What method can I use to find the angle measures?
the unit circle
Ok
can anybody help me out in proving this some how I can't understand the concept of the 2 sin theta/2 not being equal to sin theta
if you are referring to [2sin(theta)]/2
then it is indeed equal to sin(theta)
however if you are referring to 2sin(theta/2) then yes it is not
longer reason is that sin(theta) isn't a linear function, you can remember it by saying sin(60ยฐ) = โ3/2
however sin(60/2) = sin(30ยฐ) = 1/2
which is NOT equal to [sin60]/2
2sin(theta/2) is NOT equal to sin(theta) as the previous guy said, but according to trig identities,
sin(A + B) = sinAcosB + cosAsinB
hence, sin((theta/2) + (theta/2)) = 2sin(theta/2)cos(theta/2)
can someone please explain this question to me? i do not get what it is asking for
$$\lim_{x \to 1}\frac{x^{n+1}-1}{e^{x}-e}$$
wolly5114
do you divide by x both the numerator and denominator?
I am a high schooler but I suck at doing simple high-school integration. Practice isn't the thing that I need, but I can't understand anything when my teacher explains something new to me.
Using l'hopital's rule the result is simple
do you understand integration? or just how to do integration
o using factorization
If you don't understand integration, how the hell are you going to integrate?
I know how to integrate, the most basic thing. Like int x is x2/2
@lusty notch without differentiation
so polynomials in general? like x^3 + 5x^2?
Do you know the basic integration rules?
oh yes
x^4/4 + 5x^3/3
I hope I am correct
sine-> -cosine
cosine-> sine
is correct using the rule potenciation
hold up what what what?
i mean you use u sub for tan lol
dont remember
do you know substitution rule/u sub?
I mean they don't tell us why int of cos is sin. (maybe it isn't necessary?)
do you get that integration is the opposite of differentiation?
yeah but I couldn't understand it properly
you can prove the derivative of sin(x) is cos(x) using the limit definition of derivative
thats the main problem. At that time when I was learning this rule, I understood nothing
I also know that rule but I can't understand it very well either. : c
its based on the chain rule
you know the chain rule, d/dx [f(g(x))] = f'(g(x)) g'(x)?
I 'know' that my teacher taught this to me, but I coudn't understand it
is formula is long :V
do you understand the chain rule tho?
no
do you understand the limit definition of a derivative?
everything goes from the top of my head when someone explains me
is easy
i mean, do you know it in general?
oh
do you know the derivative of (2x+5)^5?
no
ahh ok
my brain flooded with confusion
u sub is based on the chain rule so i really suggest learning the chain rule first ๐
I almost don't understand Riemann's summation rule in the end.
wdym
my teacher already taught us this. I even practiced on this. But I tend to remember the procedure rather than to understand it
there's different levels of understanding
and idk how to 'understand'
there may or may not be a 'intuitive' way to think about the chain rule; if there is, I dont know it
but the limit definition of a derivative is 'intuitive' (to me), and the chain rule comes from the limit definition of a derivative, and u sub comes from the chain rule
so even if u sub or the chain rule isn't intuitive to me, i could see how it builds off of things that are
you know what i mean?
so what you mean is, if I understand limit definition, I could see how other things work? like u sub and chain rule
The thing is that not everyone learns in the same way, many learn by watching and others by reading, and others also by solving.
i meant limit definition of derivative ๐
i mean knowing the epsilon-delta definition of limit also helps bu
wow I heard that for the first time in my life
why epsilon?
you might be able to see THAT they work, but you might not have a great intuition for why it works
like the quadratic formula
you can complete the square and see THAT it works
you can understand completing the square, and you can see that completing the square gives you the quadratic formula
I learn from solving, but what to solve if I can't understand anything
but you still may not understand like intuitively why it works i guess
maybe thats a bad analogy ๐
um
I was like that too, well I still am but not as much as before, now I learn in many ways.
are you trying to understand the process, or are you trying to understand 'why' it works?
i... don't know
good for you, i also am trying...
Maybe process. yes process I guess
maybe you should practice the chain rule a lil bit more?
why
why what? why the chain rule?
why fair
Before I didn't like reading, now a little
oh because imo the 'why' is not very intuitive and seems to basically come from manipulating intuitive concepts into something that no longer seems intuitive
my opinion but ๐
how do i do number 10? i tried substitution but it js doesnt work lmao
shit
remember sin(2x) = 2sin(x)cos(x)?
i wrote it as 1/2 sinxcosx
you mean... 1/2 sin(2x)?
yeah so if u = 1/2 sin(2x), whats du?
wait where did the e go?
don't substitute in the e part
d/dx [ f(g(x))] = f'(g(x)) g'(x)
in order to use u sub, your integrand must be in this form f'(g(x)) g'(x)dx
so we let u = g(x)
in this case, we can let f(x) = e^x, and g(x) = u = 1/2 sin(2x), and then du = g'(x)dx = ?
you can use integration by parts method
naw bruh ๐ญ
why would you do that ๐ญ
i tried but i got confused lmao
huh
do you understand what im sayin or uh
๐
well thats the only thing I can remember, and if it was in our book, it would be in integration by parts method section
naw
do you get that u sub is the opposite of the chain rule?
nah this is a clear u sub
how can you say very confidently
so heres the chain rule right?
yep
because i can see u sub is much easier than IBP, most problems in an IBP section are not subbable
is du cos2x
how can you 'see' your brain
basically with the substituion rule, we hope that our integrand is in the form of the chain rule so that we can essentially do the opposite of the chain rule
If I had to tell you people my backstory, then I used to perform very well in math during primary, and secondary school. Because everything was formula-based. Now I am terrible at math
uhh i try it out a bit in my brain
like imagine you're writing it down on paper
but where paper is air
and you're not writing it down
๐
i mean its still relatively formula/technique/methodical based


