sin14°cos16° +sin104°sin164°
sin14°cos16° +sin104°sin164°
日期:2022-04-07 00:00:42 人气:1
原式=cos(180-164)sin(104-90)+sin104sin164
=cos164cos104+sin104sin164
=cos(164-104)
=cos60=0.5
=cos164cos104+sin104sin164
=cos(164-104)
=cos60=0.5