高二数学tanα=根号3/3,则cosa^2-sin(α+π/6）cosα的值是多少

高二数学tanα=根号3/3,则cosa^2-sin(α+π/6）cosα的值是多少
高二数学tanα=根号3/3,则cosa^2-sin(α+π/6）cosα的值是多少

高二数学tanα=根号3/3,则cosa^2-sin(α+π/6）cosα的值是多少
tanθ=√3/3,θ=kπ+π/6,
k为偶数时
cos^2θ-sin(θ+π/6)cosθ
=3/4-√3/2*√3/2=0
k为奇数时
cos^2θ-sin(θ+π/6)cosθ
=3/4-3/4=0