P (cos x/ 1999t) = 1/2 (V Soros Olympiad 1998-99 Round 2 10.3)
Source:
May 25, 2024
algebratrigonometry
Problem Statement
It is known that sin3x=3sinx−4sin3x. It is also easy to prove that sinnx for odd n can be represented as a polynomial of degree n of sinx. Let sin1999x=P(sinx), where P(t) is a polynomial of the 1999th degree of t. Solve the equation P(cos1999x)=21.