Question

已知函数f(x)=2cos(2x)+(sinx）^2 求f(60°）=?

Answer 1

2cos(2x)+(sinx）^2,其中,2cos(2*60°)=-1,(sin60°）^2=3/4,那么f(60°）=2cos(2*60°)+(sin60°）^2 =-1/4