已知函数f(x)=2√3sinx·cosx+cos^2x-sin^2x-1(x∈R)(1)求单调递增区间(2)若x∈[-5pai/12,pai/3]第二步要求详细点
问题描述:
已知函数f(x)=2√3sinx·cosx+cos^2x-sin^2x-1(x∈R)
(1)求单调递增区间
(2)若x∈[-5pai/12,pai/3]
第二步要求详细点
答
答:
f(x)=2√3sinxcosx+cos²x-sin²x-1
=√3sin2x+cos2x-1
=2*[sinx(√3/2)+cos2x(1/2)-1
=2sin(x+π/6)-1
(1)f(x)=2sin(x+π/6)-1的单调增区间满足:-π/2+2kπ