sin36度cos6度-sin54度cos84度等于多少
问题描述:
sin36度cos6度-sin54度cos84度等于多少
无
答
sin(36)cos(6)-sin(54)cos(84)
=sin(36)cos(6)-cos(36)sina(6)
=sin(36-6)
=sin(30)
=1/2