图像关于直线x=-π/8对称所以 f(0)=f(-π/4)sin0+acos0=sin(-π/2)+acos(-π/2)所以 a=-1 方法二：f(x)=sin2x+acos2x=√(1+a²)sin(2x+∅）最值为±√(1+a²)当 x=-π/8时,f(x)有最值所以 f(-π/8)=sin...