二倍角与半角的正弦、余弦和正切的题~1+cosa-sina 1-cosa-sina___________ + ___________数学解答

二倍角与半角的正弦、余弦和正切的题~
1+cosa-sina 1-cosa-sina
___________ + ____________ 怎么化简啊?
1-cosa-sina 1+cosa-sina
1+cosa-sina 1-cosa-sina
___________ + _____________________ 怎么化简啊？
1-cosa-sina 1+cosa-sina

人气：100 ℃　时间：2020-02-03 14:48:39

解答

(1+cos(a)-sin(a))/(1-cos(a)-sin(a))+(1-cos(a)-sin(a))/(1+cos(a)-sin(a))首先通分,公分母为:(1-sin(a))^2-(cos(a))^2=1-2*sin(a)+(sin(a))^2-(cos(a))^2=2*(sin(a))^2-2*sin(a)=2*sin(a)*(sin(a)-1)第一项分子为:...