已知函数f(x)=根号3sinxcosx+cos눀x 求(1)写出函数f(x)的最小正周期和单调递增区间

2024-12-17 16:12:44
推荐回答(1个)
回答1:

(1)f(x)=√3sinxcosx+cos²x
=√3/2sin2x+(cos2x+1)/2
=√3/2sin2x+1/2cos2x+1/2
=sin(2x+π/6)+1/2
f(x)的最小正周期为2π/2=π
2kπ-π/2≤2x+π/6≤2kπ+π/2 (k∈Z)
kπ-π/3≤x≤kπ+π/6
则f(x)的单调递增区间为[kπ-π/3,kπ+π/6] (k∈Z)

(2)2x+π/6=kπ+π/2 (k∈Z)
对称轴为x=kπ/2+π/6
因为0所以k=0
x0=π/6