已知函数f(x)=根号3sin2x+2cos^2 *x(1)求f(π/12)(2)求函数f(x)的最小正周期和单增区间
问题描述:
已知函数f(x)=根号3sin2x+2cos^2 *x(1)求f(π/12)
(2)求函数f(x)的最小正周期和单增区间
答
f(x)=√3sin2x+2(1+cos2x)/2
=√3sin2x+cos2x+1
=2(sin2xcosπ/6+cos2xsinπ/6)+1
=2sin(2x+π/6)+1
所以f(π/12)=2sinπ/3+1=√3+1
f(x)=2sin(2x+π/6)+1
所以T=2π/2=π
sin增则2kπ-π/22kπ-2π/3kπ-π/3
答
f(x)=根号(3sin2x+2cos^2 *x)=根号(3sin2x+1+cos2x)=根号[(根10)*sin(2x+t) +1] (cost=3/根号10)f(π/12)=根号(3sinπ/6+1+cosπ/6)=根号(3/2+1+根3 /2)=根号(5/2+根3 /2)(2)f(x)=根号[(根10)...