f(x)=2cos2x+sin^2x,化简.详细步骤!
问题描述：
f(x)=2cos2x+sin^2x,化简.详细步骤!
答
cos2x=cos^2 x-sin^2 x
2cos2x=2cos^2 x-2sin^2 x
f（x）=2cos^2 x-sin^2x
=cos2x+1-sin^2x
=cos2x+1+（1-cos2x）/2
=cos2x /2 +3/2