y=sin(7π/8-x)cos(x+π/8)=sin(π-(x+π/8))cos(x+π/8)=sin(x+π/8)cos(x+π/8)=1/2*2sin(x+π/8)cos(x+π/8)=1/2*sin(2x+π/4)向右平移a(a>0)个单位,y=1/2*sin(2(x-a)+π/4)=1/2*sin(2x-2a+π/4)直线x=π/4对称∴...