Mathematica does get the integral from 0 to pi/2 of log^2 cos(x) dx = 1/24 \[Pi] (\[Pi]^2+3 Log[4]^2), agreeing with you
@MrWael19705 ай бұрын
Very interesting video. Thank you.
@dwightswanson30155 ай бұрын
Truly an absolute banger!
@iWilburnYou5 ай бұрын
Love symmetric integrals
@manstuckinabox36795 ай бұрын
Ahh... the good ol massacring of integrals that make me wonder if they appear in any real life application. It's been a while since I came here, and so glad it still feels like home. always nice to see myself grow more mathematically mature along side your channel, keep it up big G!
@night95875 ай бұрын
0:54 En utilisant la methode de feyman on a integral de 0 à π/2 de ln^2(bcosx) en derivant par rapport à b on obtient inegral de 0 à π/2 de 2/b.ln(bcosx) puis on a π/2ln(b)+2/b integral de 0 à π/2 ln(cosx) changement de variable x=π/2-t on integral in(sint) qui donne 2/b×πln2/2 +k en assemblant le tout on a π/bln(b) +π/bln2 qui donne π/bln(2b) d'où M(b) =π/b×ln(2b) en integrant on a un changement de variable 2b=t la solution de l'integrale est π/2×ln^2(t)+ C en remplaçant t par 2b et b par 1 selon l'integrale originelle on obtient bien π/2×ln^2(2) + C c'est la determination du C qui pose un peu problème voilà.merci
@archinsoni12545 ай бұрын
Is integral 0 to infinity x^(-x) possible ?
@Туканчик13375 ай бұрын
Yes, Summ( 1 to inf) n^-n
@GeoPeron5 ай бұрын
BriTheMathGuy has a video on it, check it out. It's called "The integral of your dreams (or nightmares)" if I'm not mistaken
@maths_5055 ай бұрын
@GeoPeron f**k him I have a video on it 😎😎 jk check out both videos 😂
@GeoPeron5 ай бұрын
@@maths_505 You have a bunch of videos on the Gaussian, Fresnel and Dirichlet integrals, leave some to other math youtubers, damnit!
@maths_5055 ай бұрын
@@GeoPeron hell nah I'm coming for em all!!!
@chancia89905 ай бұрын
dude you're so chaotic xd
@mab93165 ай бұрын
A beauty !
@slavinojunepri76485 ай бұрын
Excellent
@robmaddock85315 ай бұрын
You're awesome
@Jalina695 ай бұрын
It is very easy! You open a bracket, then you close a bracket 😇
@Tosi314155 ай бұрын
solved last video's homework and got I=π/(2sqrt2*e^(sqrt2))
@xleph25255 ай бұрын
Solved the "HW" problem from the last video: pi * cosh( sqrt(2) ) / sqrt(2) This look alright, boss?
@maths_5055 ай бұрын
I think you made a mistake somewhere bro
@ambiguousheadline82635 ай бұрын
I believe the answer should be pi/(sqrt(2)e^sqrt(2)) if I did everything correct
@Tosi314155 ай бұрын
@@ambiguousheadline8263you probably forgot to divide by two at the end but it's correct
@dan-florinchereches489223 күн бұрын
I would like to try something else but not aure if my level of maths is jigh enough as a humble engineer :) I would like to transform 1 into sin(π/2) so 1+sin(x)=sin(π/2)+sin(x)=2sin(x/2+π/4)cos(π/4-x/2)=(using cos(a)=sin(π/2-a)) 2*cos^2(π/4-x/2) 1+sin(-x)=2sin(-x/2+π/4)cos(π/4+x/2)= 2 sin^2(π/4-x/2) All the reig functions are positive from -π/2 to π/2 so using properties of logs makes sense Function=ln(2 cos^2( π/4-x/2))ln(2 sin^2(π/4-x/2))= (ln2)^2+2ln2(ln(cos(π/4-x/2))+ln(sin(π/4-x/2)))+ln(sin^2(π/4-x/2))ln(cos^2(π/4-x/2))=(double angle sine) (ln2)^2+2ln2*ln(sin(π/2-x)/2)+ln(sin^2(...))ln(1-sin^2(...))=ln2+2(ln(cos(x))-ln2)+ln(sin^2(...))ln(1-sin^2(...)) Feels like i am going in circles as i got a factor similar to what i started with and integrating ln(cos(x)) i am not sure will evaluate nicely with Weierstrass either
@giuseppemalaguti4355 ай бұрын
sinx>cosx....formule di bisezione...4 integrali risolvibili...in verità 3/4 sono semplici,ma int(lncos(x/2)*lnsin(x/2))????
@Ayush-yj5qv5 ай бұрын
Thats what i call "AN IIT ADVANCE LEVEL" Question i tried my best couldn't solve fully
@sandyjr52255 ай бұрын
This is beyond JEE Advanced.
@Ayush-yj5qv5 ай бұрын
@@sandyjr5225 no this is the 1℅ question in jee advance that no one can solve 🥲
@julianwang79875 ай бұрын
You dropped a factor of 1/2 somewhere. The answer should have been pi/2*ln^2(2) - pi^3/12
@danielespinosa8695 ай бұрын
I agree
@michaelguenther71055 ай бұрын
At about 1:17 he redefined I to be the integral from -pi/2 to pi/2 instead of from 0 to pi/2 as at the start of the video, so for the redefined I his result is correct.
@julianwang79875 ай бұрын
@@michaelguenther7105 I think this is a bad practice. Not every viewer just wants to watch the solution right away (or at all). He could have carried a factor of 1/2 through the rest of calculation, like a presenter should do. Dropping constant factors is something I do while calculating for my own private amusement, not when I need to present the result publicly.
@Ben-wv7ht5 ай бұрын
I beg of you , change the bounds to become 0 - pi/3 , this will be MUCH MORE challenge
@yoav6135 ай бұрын
👏👏👏
@thomasolson74475 ай бұрын
I don't know what this stuff is. I have grade 12. But I'll give it a go. I have Maple and kind of understand how to use it. r[1]=cos(θ) + i*sin(θ) r[2]=-cos(θ) + i*sin(θ) f:= t -> (r[1]^t - r[2]^t)/(r[1] - r[2]) g:= t -> r[1]^t + r[2]^t int_0^n f(t) d t = ((cos(θ) + i*sin(θ))^n*ln(-cos(θ) +i*sin(θ)) - (-cos(θ) + i*sin(θ))^n*ln(cos(θ) +i*sin(θ)) + ln(cos(θ) + i*sin(θ)) - ln(-cos(θ) +i*sin(θ)))/(2*cos(θ)*ln(cos(θ) +i* sin(θ))*ln(-cos(θ) + i*sin(θ))) int_0^n g(t) = ((-cos(θ) +i*sin(θ))^n*ln(cos(θ) + i*sin(θ)) + (cos(θ) + i*sin(θ))^n*ln(-cos(θ) + i*sin(θ)) - ln(cos(θ) +i*sin(θ)) - ln(-cos(θ) + i*sin(θ)))/(ln(-cos(θ) +i* sin(θ))*ln(cos(θ) + i*sin(θ))) I graphed some of them. pi/5 looks like a 3-leaf clover. -i/2 is a sink. I suspect integrals are not meant to be used like this. *maybe a little bit of a ninja edit int_0^n f(t) d t = -(r[2]^n*ln(r[1]) - r[1]^n*ln(r[2]) - ln(r[1]) + ln(r[2]))/((r[1] - r[2])*ln(r[1])*ln(r[2])) int_0^n g(t) = (r[2]^n*ln(r[1]) + r[1]^n*ln(r[2]) - ln(r[1]) - ln(r[2]))/(ln(r[2])*ln(r[1])) Did I just do a general solution to something in polynomials?