f(x)=(1+cos2wx)/2+(√3/2)sin2wx
=sin2wx*cos(π/6)+cos2wx*sin(π/6)+1/2
=sin(2wx+π/6)+1/2
T =π=2π/2w
所以 w=1
f(x)=sin(2x+π/6)+1/2
(1)f(2π/3)=sin(4π/3+π/6)+1/2=sin(7π/6)+1/2=-1/2+1/2=0
(2) 增:
2kπ-π/2≤2x+π/6≤2kπ+π/2
2kπ-2π/3≤2x≤2kπ+π/3
kπ-π/3≤x≤kπ+π/6
增区间为 【kπ-π/3,kπ+π/6】,k∈Z
减:
2kπ+π/2≤2x+π/6≤2kπ+3π/2
2kπ+π/3≤2x≤2kπ+4π/3
kπ+π/6≤x≤kπ+2π/3
减区间为 【kπ+π/6,kπ+2π/3】,k∈Z
2x+π/6=kπ+π/2
2x=kπ+π/3
对称轴方程 x=kπ/2+π/6,k∈Zf(2π/3)为什么我算的等于-1/2 是我错了么??我算错了,抱歉 f(2π/3)=sin(4π/3+π/6)+1/2=sin(3π/2)+1/2=-1+1/2=-1/2
已知函数f(x)=cos^2(wx)+根3sinwxcoswx(w>0)的最小正周期为π.
已知函数f(x)=cos^2(wx)+根3sinwxcoswx(w>0)的最小正周期为π.
(1)求f(2π/3)的值
(2)求函数f(x)的单调区间及其图像的对称轴方程.
(1)求f(2π/3)的值
(2)求函数f(x)的单调区间及其图像的对称轴方程.
数学人气:285 ℃时间:2020-04-03 15:59:12
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