1.
f(x)=2cosx(cosx+√3sin)-1
=2(cosx)^2-1+2√3sinxcosx
=√3sin2x+cos2x
=2sin(2x+π/6)
所以f(x)的最小正周期T=2π/2=π
2.
求f(x)的单调递增区间
令2kπ-π/2<2x+π/6<2kπ+π/2(k∈Z)得
kπ-π/3<x<kπ+π/6(k∈Z)
那么f(x)的单调递增区间是(kπ-π/3,kπ+π/6)(k∈Z)
如果不懂,请Hi我,祝学习愉快!
1.
f(x)=2cosx(cosx+√3sin)-1
=2(cosx)^2-1+2√3sinxcosx
=√3sin2x+cos2x
=2sin(2x+π/6)
所以f(x)的最小正周期T=2π/2=π
2.
求f(x)的单调递增区间
令2kπ-π/2<2x+π/6<2kπ+π/2(k∈Z)得
kπ-π/3<x<kπ+π/6(k∈Z)
那么f(x)的单调递增区间是(kπ-π/3,kπ+π/6)(k∈Z)
如果不懂,请Hi我,祝学习愉快!