# Polynomial equation $f(x)f(2x^2)=f(2x^3+x)$ [duplicate]

Find all polynomials $f(x)$, for which $f(x)f(2x^2)=f(2x^3+x)$.

I have no idea how to do it.

• I think this question should be reopened, as this question was closed as being a duplicate of this current one. (So a "good" question is a duplicate of a "bad" question...) – user1729 Jan 24 '18 at 13:49