cos(-47∏/12)=?
答案:3 悬赏:30 手机版
解决时间 2021-03-06 05:19
- 提问者网友：焚苦与心
- 2021-03-06 01:25
cos(-47∏/12)=?
最佳答案
- 五星知识达人网友：慢性怪人
- 2021-03-06 02:17
cos(-47π/12)
=cos(47π/12)
=cos(4π -π/12)
=cos(π/12)
=√[(cos(π/6) +1)/2]
=√[(√3/2 +1)/2]
=(1/2) √(√3+2)
=√2.(√3+1)/4
------------
(√3+2)
= (1/2)(2√3+4)
= (1/2)(√3+1)^2
√(√3+2) = (√3+1)/√2 = √2.(√3+1)/2
=cos(47π/12)
=cos(4π -π/12)
=cos(π/12)
=√[(cos(π/6) +1)/2]
=√[(√3/2 +1)/2]
=(1/2) √(√3+2)
=√2.(√3+1)/4
------------
(√3+2)
= (1/2)(2√3+4)
= (1/2)(√3+1)^2
√(√3+2) = (√3+1)/√2 = √2.(√3+1)/2
全部回答
- 1楼网友：三千妖杀
- 2021-03-06 04:18
图
- 2楼网友：痴妹与他
- 2021-03-06 03:38
cos(-47π/12)=
=cos(-3.92π)
≈0.966
我要举报
如以上问答信息为低俗、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！
大家都在看
推荐资讯