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SQT - Stupid Questions
Jose Barnes
Cameron Evans
Is this the Stupid Questions Thread?
Parker Rodriguez
I'm doing integral of e^(-st) t sin(t)dt from 0 to inf
and I get -2s/((1 + s^2)^2)
But wolframalpha says the answer is the positive version: 2s/((1 + s^2)^2)
I can't see where I'm going wrong. Can someone post the step-by-step?
Cooper Howard
you probably just fucked up a negative somewhere. Maybe the - in (-st)
Aiden Morales
how are we supposed to know what you did wrong when you dont show us any of your work brainlet?
Jaxon Clark
just take the Laplace transform of sin(t) and differciate with respect to s.
ta da
differentiation under the integral sign is ur best friend
Jack Gray
Underated
Aaron Miller
Write an arbitrary vector in a basis of eigenvectors of M, then swap all the eigenvalues out with the maximal/minimal eigenvalue?
Nathaniel Morgan
since M is real symmetric its diagonalizable with eigenvectors e1,..., en with eigenvalues c1,..,cn
write x = sum of aiei
then
x^T M x
=(sum aiei)^T M (sum aiei)
=(sum aiei)^T sum aiciei)
=sum ai^2ci
Angel Edwards
should be
>= sum ai^2 min{ci}
on the last line of course