ok so i've been given the equation
(S=integrate between infinity and 0 and n = pi)
S(sin(ax)/sinh(bx))dx = (n/2b)tanh(na/2b)
and have been told to take a derivative of it in order to evaluate the following
S(xcos(ax)/sinh(bx))dx
am I correct in thinking that i simply need to differentiate the right hand side of the above with respect to a in order to get my answer or should i be differentiating with respect to b as well?
I have been given the result that:
if S (f(t,x)) dt = A(x)
then S {d[f(t,x)]/dx}dt = A'(x)
but wondered if this can be applied to functions with a third variable such that:
if S (F(t,x,y)) dt = A(x,y)
then S {dF/dy +dF/dx}dt = dA/dx + dA/dy
Or am I barking up the wrong tree?