If f is irreducible and |f(0)| not a square then f(x^2) irr.
Source: Romanian IMO Team Selection Test TST 2003, problem 5
September 24, 2005
algebrapolynomialcalculusintegrationfunctioncomplex numbersabsolute value
Problem Statement
Let be an irreducible polynomial over the ring of integer polynomials, such that is not a perfect square. Prove that if the leading coefficient of is 1 (the coefficient of the term having the highest degree in ) then is also irreducible in the ring of integer polynomials.
Mihai Piticari