由于函数y=sin2x+2sin2x=sin2x+1-cos2x=2sin(2x−π4)+1，而函数y=sint的对称轴为t＝kπ+π2则2x−π4＝kπ+π2，解得x＝kπ2+3π8（k∈Z）则函数y=sin2x+2sin2x的对称轴方程为x＝kπ2+3π8(k∈Z)故答案为x＝kπ2+3...