Q63. Let f be a continous, strictly decreasing, real-valued function such that
is finite and f(0)=1.
In terms of
(the inverse function of f),
I tried using the "Inverse Function Integration method":
Is the method valid?
Also, how do we conclude that xf(x)=0, when x is infinity? (x would be infinity while f(x)=0)
Lastly, is there any faster method?
Thank you very much.