-tan*2 x / 1+ tan*2x
= ?
答案-sin*2x
步驟係點?
更新1:
好似打錯左,答案sin*2x 冇負,係咪??
問數,關於tanx
回答 (1)
2008-06-08 7:31 am
✔ 最佳答案
-tan^2 x / (1+ tan^2x)=-tan^2x/(1+sin^2x/cos^2x)
=-tan^2x/(sin^2x+cos^2x)/cos^2x
=-tan^2x(cos^2x)
=(-sin^2x)(cos^2x)/cos^2x
=-sin^2x //
收錄日期: 2021-04-19 01:14:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080607000051KK03330