函数f(x)=sin²(x+π/4)+cos²(x-π/4)-1,f（x)是周期为多少?f(x)=sin²(x+π/4)-[1-cos²(x-π/4)]=sin²(x+π/4)-sin²(x-π/4)=[sin(x+π/4)+sin(x-π/4)][sin(x+π/4)-sin(x-π/4)]=[2s...