cos105-sin105等于
1个回答
=cos(60+45)-sin(60+45)
=cos60cos45-sin60sin45-sin60cos45-cos60sin45
=-√6/2
相关问题
sin105°cos105°
sin165°cos75°+cos15°sin105°等于?
sin15°cos75°+cos15°sin105°等于多少?
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°)
sin(x+105°)cos(x-15°)-cos(x+105°)sin求化简
cos105°+sin195°
sin105°•cos75°=______.
用两角和的余弦求 cos15°cos105°+sin15°sin105°