Given a polynomial
$$ y(x) = a_0 + a_1 x + a_2 x^2 +... a_k x^k $$
I'm told there exists a transformation $\phi: x \rightarrow F(a_0 , a_1 ... a_k , x) $ such that
$$ y(\phi(x)) = e_0 + e_1 \phi + e_2 \phi^k $$
But i'm not sure how to derive the form of this operation in the general case.