求值sin29/6π cos31/4π tan(-1560°)
问题描述:
求值sin29/6π cos31/4π tan(-1560°)
答
sin29/6π cos31/4π tan(-1560°)=sin(4π+5/6π) cos(8π-1/4π )tan(-5*360°+240°)=sin5/6π cos1/4π tan240°=sin(π-1/6π) cos1/4π tan(180°+60°)=sin1/6π cos1/4π tan60°=1/2*√2/2*√3=√6/4...