已知向量m=(2√3sin(x/4),2),向量n=(cos(x/4),cos^2(x/4)),函数f(x)= 向量m×向量n
问题描述:
已知向量m=(2√3sin(x/4),2),向量n=(cos(x/4),cos^2(x/4)),函数f(x)= 向量m×向量n
1、求函数f(x)的最小正周期
2、若f(a)=2,求cos(a+π/3)的值
答
1,f(x) =2√3sin(x/4)xcos(x/4)+2cos^2(x/4)=√3sin(x/2)+cos(x/2)+1=2sin(x/2+π/6)+1 f(x)的最小正周期 T =2π/w =4π,2, f(a ) =2sin(a/2+π/6)+1=2求出 a=4kπ或4/3π+4kπ( k属于z)cos(a+π/3)=...