2[2sin(x+π/6)×cosx]化简得?
问题描述：
2[2sin(x+π/6)×cosx]化简得?
答
原式=2(sinxcosπ/6+cosxsinπ/6)cosx=√3sinxcosx+cos^2x
=2x√3/2sinxcosx+2cos^2x-1/2+1/2=√3/2sin2x+cos2x/2+1/2
=sin(2x+π/6)+1/2