3sinx-根号3cosx=2根号3sin(x+α).α属于(-π,π),则α的值是
问题描述:
3sinx-根号3cosx=2根号3sin(x+α).α属于(-π,π),则α的值是
答
左边=2√3(sinx*√3/2-cosx*1/2)
=2√3(sinxcosπ/6+cosxsinπ/6)
=2√3sin(x-π/6)
所以α=-π/6