But you don't have the
So i guess we should actually find the integral and evaluate it between those limits to find f(x) and hence f(1/x). But i don't want to waste my time doing this if we don't have to, so:
(1) Check if there is a typo here and that we should actually have a somewhere, or
(2) If we can still apply the second fundamental theorem of calculus, could someone please confirm that?