函数f(x)=sin(π-x)sin(pai5/2-x)+cos^2x
=sinx*cosx+cos^2x
=1/2sin2x+1/2cos2x+1/2
=根号2sin(2x+π/4)+1/2
最小正周期=2π/2=π
2kπ-π/2应该是函数f(x)=sin(π-x)sin(pai/2-x)+cos^2x一样的