MathDB

4

Part of 1995 Austrian-Polish Competition

Problems(1)

P(x)^2 + P(1/x)^2= P(x^2)P(1/x^2)

Source: Austrian - Polish 1995 APMC

5/3/2020
Determine all polynomials P(x)P(x) with real coefficients such that P(x)2+P(1x)2=P(x2)P(1x2)P(x)^2 + P\left(\frac{1}{x}\right)^2= P(x^2)P\left(\frac{1}{x^2}\right) for all xx.
functional equationfunctionalpolynomialalgebra