化简得((根号2)/2)*(sin(2x-π/4))+1/2.f(x)=a*a+b*b=(sinx)^2+(cosx)^2+sinxcosx-(cosx)^2=(1-(cos2x))/2+((sin2x)/2)=sin(a+b)公式收拢即为：((根号2)/2)*(sin(2x-π/4))+1/2.所以T=(2π)/2=π