cos585° +tan(-120° ) + sin300° + cot(-570°)
=cos(720-135)+tan(-180+60)+sin(360-60)+cot(-720+150)
=cos(135)+tan(60)+sin(-60)+cot(150)
=-√2/2+√3-√3/2-√3
=-(√2+√3)/2
你能明白,赞同
cos585° +tan(-120° ) + sin300° + cot(-570°)
=cos(720-135)+tan(-180+60)+sin(360-60)+cot(-720+150)
=cos(135)+tan(60)+sin(-60)+cot(150)
=-√2/2+√3-√3/2-√3
=-(√2+√3)/2
你能明白,赞同