Studying for a qualifying exam and came across Don Marshall's notes. This one has stumped me for some time. This question is related to another MSE question:
$\begin{align*}\text{If $f$ and $g$ are entire and } [f(z)]^n+[g(z)]^n=1\text{ for $n>3$ then $f,g$ are constant}. \end{align*}$
The most I could deduce is that if $f$ were not constant then $[f(z)]^n$ is necessarily surjective as missing one value for $[f(z)]^n$ would force $n$ missed values for $f$. That's about as far as I could get.