计算4/3[cos^2(13π/6)]+3tan^2(π/6)-1/3[sin^2(2π/3)],
问题描述：
计算4/3[cos^2(13π/6)]+3tan^2(π/6)-1/3[sin^2(2π/3)],
答
(4/3)*cos²(13π/6)+3tan²(π/6)-(1/3)*sin²(2π/3)=(4/3)*cos²(π/6)+3tan²(π/6)-(1/3)*sin²(π/3)=(4/3)*(√3/2)²+3*(√3/3)²-(1/3)*(√3/2)²=(4/3)*(3/4)+3*(1/3)...