f(x)=√2(√2/2sin(2x+π/4)+√2/2cos(2x+π/4))=√2(cos(π/4)sin(2x+π/4)+sin(π/4)cos(2x+π/4))==√2sin(2x+π/2)=√2cos2x是根据公式：asinx+bcosx=√ (a^2+b^2)sin (x+θ）,其中sinθ=b/ √(a^2+b^2) ,cosθ=...