Contact us
Choose a category below so we can get back to you as quickly as possible.
解(sin²;a-cos²;a)=(sin²;a-cos²;a)/(sin²;a+cos²;a)——除以1,值不變=(tan²;a-1)/(tan²;a+1)——分子分母同時除以cos²;a=(1/4-1)/(1/4+1)=-3/4×(4/5)=-3/5
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.