y=2sin(π/4+x/2)sin(π/4-x/2) =2sin(π/4+x/2)sin[π/2-(π/4+x/2)] =2sin(π/4+x/2)cos(π/4+x/2) =sin(π/2+x) =cosx故对称轴为x=kπ（k∈Z)若满意请采纳！！谢谢
