已知tanα=-2,求(1+sin2α)/(2cos^2α+sin2α)的值
人气：424 ℃ 时间：2020-02-05 10:55:12
解答
==》{(sina+cosa)^2 } / (2cos^2α+sin2α) ={(sina+cosa)^2 } / 2 *cosa *(sina + cosa ) =
(sina + cosa )/2*cosa = 1/2*( tana+1)=-1/2
推荐
猜你喜欢
- 设△ABC的重心和外心分别为D,E,已知A（0,-1）B（0,1）,且向量DE∥AB,求顶点C的轨迹方程.
- 英语翻译
- 1.若(a+1)x三次方*yb次方-2次方是关于x,y的七次单项式,则a,b满足什么条件?2.已知多项式-5分之x的2次方
- 相信我能胜任这份工作的英文
- 满载而归,漫不经心,茅塞顿开,美不胜收,门庭若市,名副其实!
- he couldn't persuade her to change her mind,no matter how hard he ___ try
- A:_______________?B：It was interesting,but there were too many people.现在就要啊
- 人教版初三上册语文第25课解析
