2sinx+cosx=1
2sinx=1-cosx
4sin^2x=1-2cosx+cos^2x呢步點黎
a math
2008-01-11 12:18 am
回答 (2)
2008-01-11 12:24 am
✔ 最佳答案
2sinx=1-cosx(2sinx)²=(1-cosx)²
4sin²x=1-2cosx+cos²x
2008-01-11 12:27 am
2sinx+cosx=1..................(1)
2sinx=1-cosx...................(2)
From (1),
2sinx=1-cosx...............(3)
(1)x(3),
(2sinx)(2sinx)=(1-cosx)(1-cosx)
4sin^2x=1-2cosx+cos^2x
2sinx=1-cosx...................(2)
From (1),
2sinx=1-cosx...............(3)
(1)x(3),
(2sinx)(2sinx)=(1-cosx)(1-cosx)
4sin^2x=1-2cosx+cos^2x
參考: on my own...
收錄日期: 2021-04-23 22:27:57
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080110000051KK02110