1) 1/1-cosθ - 1+cosθ/sin^2θ
2) (1- 1/cosθ) (1/cosθ + 1)
唔該要步驟~~!!急!!10點,thanks~~!!
收錄日期: 2021-04-22 00:42:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090615000051KK00046