函数f(x)=2cos²(x-π/4)-1的周期为

问题描述:

函数f(x)=2cos²(x-π/4)-1的周期为

根据cos2a=2cos²a-1得
f(x)=2cos²(x-π/4)-1
=cos2(x-π/4)
=sin(2x-π/2)
=-cos2x
∴ T=2π/2=π