Integrating Indefinite Integrals of Single Variables and Unknown Functions

Hi,

I have what looks like an exceptionally difficult indefinite integral, which I’d much rather (for very obvious time and complexity reasons) perform computationally. The function itself is of a single variable, but contains an unknown function of this same single variable, e.g. in a simple, reductive form:

G(x) = A*x*f(x) , where A is a constant and f(x) is not known

My question(s) is(are) a. whether it’s possible to perform an integration of this nature in Matlab; b. if it is, how would I define this unknown function and latterly apply the integration.

Many thanks