已知向量a=(2cosx,-1),向量b=(sin(x+π/3),(根号3)/2),函数f(x)=向量a*向量b
问题描述:
已知向量a=(2cosx,-1),向量b=(sin(x+π/3),(根号3)/2),函数f(x)=向量a*向量b
1.求f(x)的最小正周期;
2.若x属于[0,π/2],求f(x)的值域.
答
f(x)=a*b
=2cosxsin(x+π/3)-√3/2
=sin(2x+π/3)
(1) T=2π/2=π
(2) x∈[0,π/2],y∈[-√3/2,1]