已知sin(0.25pi-x)=5/13,0<x<0.25pi,求cos2x/cos(0.25pi+x)
答案:1 悬赏:80 手机版
解决时间 2021-04-06 12:13
- 提问者网友：练爱
- 2021-04-05 18:40
已知sin(0.25pi-x)=5/13,0<x<0.25pi,求cos2x/cos(0.25pi+x)
最佳答案
- 五星知识达人网友：走死在岁月里
- 2021-04-05 20:19
cos2x/cos(0.25pi+x)
=sin(pi/2-2x)/sin(0.5pi-(0.25pi+x))
=2sin(0.25pi-x)*cos(0.25pi-a)/sin(0.25pi-x)
=2cos(0.25pi-x)
已知sin(0.25pi-x)=5/13,0
就有 24/13
=sin(pi/2-2x)/sin(0.5pi-(0.25pi+x))
=2sin(0.25pi-x)*cos(0.25pi-a)/sin(0.25pi-x)
=2cos(0.25pi-x)
已知sin(0.25pi-x)=5/13,0
就有 24/13
我要举报
如以上回答内容为低俗、色情、不良、暴力、侵权、涉及违法等信息，可以点下面链接进行举报！
点此我要举报以上问答信息
大家都在看
推荐资讯