sin15°cos^315°-cos15°sin^315°化简

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/17 13:39:14

原式=sin 15° cos 15° [ (cos 15°)^2 -(sin 15°)^2 ]
=(1/2) *(2 sin 15° cos 15°) *cos 30°
=(1/2) *sin 30° *(根号3)/2
=(1/2) *(1/2) *(根号3)/2
= (根号3)/8.
= = = = = = = = =
分解因式,再用二倍角公式.
已用计算器验证.

sin15°cos^315°-cos15°sin^315°化简求cos15°-tan15°/cos15°+sin15° (cos15°-cos75°)(sin75°+sin15°)＝? tan15°+cos15°/sin15°的值求详解求sin15°+tan30°cos15°的值化简1：cos(15°-a)sin15°-sin(165°+a)cos(-15°) sin15° 1.sin7°+cos15°sin8°/cos7°-sin15°cos8°= 求值(sin9°cos15°-sin24°)/(sin9°sin15°+cos24°) (sin7°+cos15°cos8°)/(sin7°-sin15°sin8°)的化简 tan15°、tan75°sin15°、sin75°、cos15°cos75°具体数值 cos15°sin9°+sin6°/sin15°sin9°—cos6°=