y=2sinx(sinx+cosx)
=2sinxsinx+2sinxcosx
=-（1-2sinxsinx-1+sin2x)
=-(cos2x+sin2x-1)
=-根号2（（根号2）/2 *cos2x+（根号2）/2 *sin2x)+1
=-根号2sin(2x+π/4)+1