f(x)=sin(π-x)sin(π/2 -x)+cos²x
=sinxcosx+cos²x
=1/2*sin2x+(1+cos2x)/2
=1/2*(sin2x+cos2x)+1/2
=√2/2*sin(2x+π/4)+1/2
最小正周期T=2π/2=π
f(x)=sin(π-x)sin(π/2 -x)+cos²x
=sinxcosx+cos²x
=1/2*sin2x+(1+cos2x)/2
=1/2*(sin2x+cos2x)+1/2
=√2/2*sin(2x+π/4)+1/2
最小正周期T=2π/2=π