y=2sin^2 x+4sinxcosx+5cos^2 x 化简
问题描述：
y=2sin^2 x+4sinxcosx+5cos^2 x 化简
答
y=2sin^2 x+4sinxcosx+5cos^2 x =2sin^2 x+2sin2 x++5cos^2 x =(1-cos2x)+2sin2 x+5(1+cos2x)/2=7/2+4cos2x+2sin2 x