已知f(x)=2cosx(sinx-cosx)+2,x∈R,化简成Asin(ωx+ψ)+B(A>0,ω>0,|ψ│

f(x)=2cosxsinx-2cosxcosx+2
=sin2x-cos2x+3
=根号2sin(2x-π /4)+3
T=π 初相为2