求值sin17/6π,cos(-43π/6),tan(-1560°)

题目

求值sin17/6π,cos(-43π/6),tan(-1560°)

答案

sin17/6π=sin(2π+5π/6)=sin5π/6=sin(π-π/6)=sinπ/6=1/2cos(-43π/6)=cos43π/6=cos(6π+7π/6)=cos7π/6=cos(π+π/6)=-cosπ/6=-根号3/2tan(-1560°)=-tan1560°=-tan(1440°+120°)=-tan120°=-tan(180°-6...