Do one integral where feynman’s trick fails due to divergence
@shivanshnigam4015 Жыл бұрын
Integral from 0 to infinity (e^-x-1)/x
@pacolibre5411 Жыл бұрын
I mean, if the integral is divergent anyway, then whether or not you can use Feynman’s rule is kinda moot, isn’t it? It’s basically saying “Feynman’s rule can’t help us find the answer because the answer doesn’t exist.” Which doesn’t really have anything to do with the rule itself. You’d have to find a function with a limit that converges if you do it in one order, but diverges as a mixed limit, for the hypotheses of the rule to matter.
@DD-ce4nd Жыл бұрын
When changing x^2 into x^s, the integral has the closed form: 1/4*GAMMA(1/2*(s+1)/s)*2^(1/s)*(2*ln(2)+Psi(1/2*(s+1)/s)+Psi(1/2*(2*s-1)/s))*Pi^(1/2)/s^2/GAMMA(1/2*(2*s-1)/s) for s in R, s > 1 (and provides the analytic continuation to a wider domain). Psi(z) is the Digamma-function. Limit s -> 1 yields -gamma.
@mokhtarmougai5088 Жыл бұрын
I love the laplace transform ❤
@mekbebtamrat817 Жыл бұрын
Great work
@cadmio94133 ай бұрын
Thanks for teaching us all this methods, have been from HUGHE help for me to continue studying calculus by myself, I'm so grateful by all your effort, keep it up man :>
@riadsouissi Жыл бұрын
I did it a bit differently. I=integral (laplace(sin(x))*inverse_laplace(log(x)/sqrt(x)). The inverse laplace transform of log(x)/sqrt(x) can be solved by assuming it is equal to (a+b*log(x))/sqrt(x) (a bit similar to log(x)/x) then applying the laplace transform, we can find a and b. The integral after that becomes easier to solve.
@MrWael1970 Жыл бұрын
Thank you for your innovative video.
@omarino99 Жыл бұрын
Watching the plot of this thing I can barely believe someone managed to computer its integral exactly… it looks like the crazy functions I had fun coming up with in high school just to see how they’d look like.
@maths_505 Жыл бұрын
Well that's one way of generating cool integrals
@Noam_.Menashe Жыл бұрын
You can pretty easily show the integral with the complex exponential is equal to the same one but with a negative exponent (gamma function integral form) multiplied by a constant factor using complex integration.
@192chickenking Жыл бұрын
how? can you explain more? i want to try without laplace way
@Noam_.Menashe Жыл бұрын
@@192chickenking search "Cauchy integration thereon". It's an analytic function and use a quarter circle contour.
@192chickenking Жыл бұрын
@@Noam_.Menashe thanks, i see . i thought there was another substitution instead of contour integral lol
@manstuckinabox3679 Жыл бұрын
Ah such a satisfying Journey, really brings out the ln(x) in me.
@timemasterdm2462 Жыл бұрын
I hope you get better soon, prof. Bro.
@artham6565 Жыл бұрын
At 7:30 ..... Cos is taken as an imaginary part?? ?? please explain sir...i didn't understand
@maths_505 Жыл бұрын
Phase shift of pi/2 turns a trig ratio into its co ratio
@artham6565 Жыл бұрын
@@maths_505 ohh...yes...got it...mind lag....😂😂
@PhysicsNg Жыл бұрын
❤
@cadmio94133 ай бұрын
Why is no one in the comments using the Ramanujan Master Theorem???
@giacomocervelli1945 Жыл бұрын
Nice solution, but i think the Laplace transform part was unncessary, you could have just spammed integration by parts
@firmkillernate Жыл бұрын
We watch for elegance, not for vigor
@giacomocervelli1945 Жыл бұрын
I do also prefer elegance, but using higher level stuff when you can do it equally easy with elementary tools is not that elegant
@giacomocervelli1945 Жыл бұрын
Still, thats my opinion, yours may differ
@sergten Жыл бұрын
Great one. The integral-calculator site had it slightly differently, basically reverting the sign in the parentheses by prepending them by (i - 1)(i + 1) and then rewriting the denominator as 2^(9/2), and rewriting 2*ln(4) as 4*ln(2). I'm amazed that it found an analytical solution. Now I'm curious how that Maxima computer algebra system works.
@nightmareintegral5593 Жыл бұрын
Sweat integral ❤
@ripjawsquad Жыл бұрын
Sweat
@امینظاهرزاده Жыл бұрын
Integral (-1)^[x]? This what?
@GiornoYoshikage Жыл бұрын
Figured out the solution in few seconds. Still, cool stuff!
@maths_505 Жыл бұрын
Guess I've left a bad impression on the homies😂
@fartoxedm5638 Жыл бұрын
Nice one! I used Ramanujan master theorem btw
@appybane8481 Жыл бұрын
My way is similar to how you Integrate sinx*lnx/x from 0 to inf.