To find an equation whose roots are a transformation of the roots of a given equation, substitute the relationship between the new roots and the old roots into the original equation. If the roots are $x_i$ and the new roots are $y_i = f(x_i)$, then express $x_i$ in terms of $y_i$, i.e., $x_i = f^{-1}(y_i)$, and substitute this into the original polynomial.