求值cos(2arctan根号6+pai/3)

问题描述:

求值cos(2arctan根号6+pai/3)

cos(2arctan根号6+π/3)=cos(2arctan根号6)cos(π/3)-sin(2arctan根号6)sin(π/3)={2cos^2(arctan根号6)-1}*1/2-2sin(arctan根号6)cos(arctan根号6)*1/2*根号3=cos^2(arctan根号6)-1/2-sin(arctan根号6)cos(ar...