# More direct way to derive indirect utility function from expenditure function

I have this general form for a expenditure function $e(p,u)=f(u)\cdot g(p)$ where $f(u)$ is increasing monotonic. How can I derive a functional form for an indirect utility function from this expenditure function?

• Thanks a lot! Do you know how could I prove that income elasticity is unitary for each $x_{i}$ ? Oct 19 '16 at 13:00