已知函数fx=cos^2(x-pai/6)-sin^2(x)
问题描述:
已知函数fx=cos^2(x-pai/6)-sin^2(x)
(1)、求f(12/pai)
(2)、求函数fx在[0,pai/2]上的最大值
答
(1)f(x)= [cos(x-π/6)]^2 - (sinx)^2f(π/12) = (cos(π/12))^2 - (sin(π/12))^2=cos(π/6)=√3/2(2)f(x) =[cos(x-π/6)]^2 - (sinx)^2= [(√3/2)cosx + (1/2)sinx]^2 - (sinx)^2= (1/4)( 3(cosx)^2 + 2√3sinxcos...