cos12*cos98-sin12*sin98=?
2个回答
cos12*cos98-sin12*sin98
=cos(12+98)
=cos120
=-cos60
=-1/2
相关问题
cos12°cos98°-sin12°sin98°=
cos12度cos98度-sin12度sin98度=什么?
cos12度×cos98度-sin12度×cos8度 =多少
(cos[π/12-sinπ12])(cos[π/12+sinπ12])= ___ .
cos72(cos72-cos12)+sin72(sin72-sin12)答案是0.
求值:cos105°cos15°-sin105°sin15°=−12−12.
三角代换问题2*sin(∏/12)*(sin(∏/6))怎样化为cos(∏/12)-cos(3*∏/12)?
(cos30度sin18度+sin12度)/(sin30度sin18度-cos12度)
cos*π/12—sin*π/12
sin(π/12)-cos(π/12)=