原式=√2sinx-sinxcosπ/4+cosxsinπ/4
=√2sinx-sinx*√2/2+cosxsinπ/4
=sinx*√2/2+cosxsinπ/4
=sinxcos π/4+cosxsinπ/4
=sin(x+π/4)答案是 sin(x/2+π/4)错了采纳吧