MathDB

4

Part of 1979 Vietnam National Olympiad

Problems(1)

there is a polynomial p(x) such that p(2 cos x) = 2 cos nx., for every n>0

Source: Vietnam MO 1979 P4

7/28/2018
For each integer n>0n > 0 show that there is a polynomial p(x)p(x) such that p(2cosx)=2cosnxp(2 cos x) = 2 cos nx.
polynomialtrigonometryalgebra