已知函数f(x)=(sinx)^2+根号三sinxcosx+2(cosx)^2,x属于R求f(π/12)
问题描述:
已知函数f(x)=(sinx)^2+根号三sinxcosx+2(cosx)^2,x属于R求f(π/12)
答
f(x)=sin²x+√3sinxcosx+2cos²x=(1-cos2x)/2+√3/2(2sinxcosx)+(1+cos2x)=(1-cos2x)/2+√3/2sin2x+(1+cos2x)∴f(π/12) =(1-cosπ/6)/2+√3/2sinπ/6+(1+cosπ/6)=(1-√3/2)/2+√3/2*1/2+(1+√3/2)=3...