已知函数f(x)=sin^2x+2倍根号下3sinxcosx+3cos^2x.求函数的单调递增区间
问题描述：
已知函数f(x)=sin^2x+2倍根号下3sinxcosx+3cos^2x.求函数的单调递增区间
答
2倍根号下即是外面用两个根号？
答
f(x)=sin^2x+2√3sinxcosx+3cos^2x
=(sinx+√3cosx)^2
=[sin(π/6+x)]^2
2kπ 2kπ-π/6
答
f(x)=sin^2x+2√3sinxcosx+3cos^2x
=(sinx+√3cosx)^2
=[sin(π/6+x)]^2
2kπ