Let A = Integral [0...inf] f(t)dt, A>0.
Suppose I have the following integral: B=Integral [0...inf] f(t)*exp(-kt)dt where k>0 is a constant. Is it possible to have a bound for B (upper or lower) in terms of A and k? I tried Cauchy-Schwarz but that only gets you to integral of f(t)^2 and not sure if I can express this in terms of A somehow...