sin165°cos75°+cos15°sin105°等于?
4个回答
原式=sin(180-15)cos75+cos75sin(180-75)
-sin15cos75+cos75sin75
=sin(15+75)
=sin90
=1
相关问题
sin15°cos75°+cos15°sin105°等于多少?
sin15°cos75°+cos165°sin75°
化简sin15°cos75°+cos15°sin105°=______.
化简sin15°cos75°+cos15°sin105°=______.
cos(15-a)cos75-sin(165+a)cos(-15)=
sin105°•cos75°=______.
sin15cos75+cos平方15等于
Sin75°/Cos75°+Cos75°/Sin15°=?
sin(a+105)cos(a-15)-cos(a+105)sin(a-15)
求值:cos105°cos15°-sin105°sin15°=−12−12.