图像关于x=-π/8对称,则图像在x=-π/8处取到最大值或最小值令原式=√(1+λ^2) sin(2x+θ)则当x=-π/8时,2x+θ=kπ+π/2θ=kπ+3π/4则原式=√(1+λ^2) sin(2x+kπ+3π/4)=√(1+λ^2)sin2xcos(kπ+3π/4)+√(1+λ^2) ...