Question 3
Find all real polynomials of degree $n$ satisfying
$$
P(P(x) + x) = P(P(x)) + P(x)^n + 1.
$$
$$
P(P(x) + x) = P(P(x)) + P(x)^n + 1.
$$
MathNet 2015-part-04 — 191 problems (EN–VI) Question 3
Math Olympiad Vault · MathNet 2015-part-04 — 191 problems (EN–VI)