cos105°+sin195°
3个回答
原式=cos(90+15)+sin(180+15)
=-sin15-sin15
=-2sin(45-30)
=-(sin45cos30-cos45sin30)
=(√2-√6)/2
相关问题
sin105°cos105°
cos105-sin105等于
sin(a+105)cos(a-15)-cos(a+105)sin(a-15)
求值:cos105°cos15°-sin105°sin15°=−12−12.
sin(x+105°)cos(x-15°)-cos(x+105°)sin(x-15°)
|sin165°|*cos15°-sin225°*|sin195°|的值
sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简
sin105°•cos75°=______.
sin165°cos75°+cos15°sin105°等于?
求值cos75°;求值cos195°;cos54°cos36°-sin54°sin36°