4sinxcos^2x/2=2sinx+sin2x 要过程证明左=右

解法如下:
左边=2sinx*2cos^2(x/2)
=2sinx*[2cos^2(x/2)-1+1]
=2sinx*(cosx+1)
=2sinxcosx+2sinx
=sin2x+2sinx
=右边

右=2sinx+2sinxcosx
=2sinx(1+cosx)
=2sinx(1+2cos^2(x/2)-1)
=4sinxcos^2(x/2)
=左

2sinx+sin2x
=2sinx+2sinxcosx
=2sinx(1+cosx）
=2sinx（1+（2cos^2x/2-1))
=4sinxcos^2x/2