6tanx = 5cscx
Find x if 0<= x <= 2pi or 360
三角問題12-07-2013
2013-07-13 6:47 am
回答 (1)
2013-07-13 6:22 pm
✔ 最佳答案
6tan x = 5csc x6sin x / cos x = 5 / sin x
6sin² x = 5cos x
6(1 - cos² x) = 5cos x
6cos² x + 5cos x - 6 = 0
(2cos x + 3) (3cos x - 2) = 0
cos x = - 3/2 (rejected)
or cos x = 2/3
x = 0.841 = 48.19° or x = 5.442 = 311.81°
收錄日期: 2021-04-21 22:27:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130712000051KK00391