M2 Q. Tri. function 快 20分!
回答 (2)
2011-02-28 4:46 pm
✔ 最佳答案
tan 2A + 2 cot A= 2 tan A/(1 - tan2 A) + 2/tan A
= [2 tan2 A + 2(1 - tan2 A)]/[tan A(1 - tan2 A)]
= 2/[tan A(1 - tan2 A)]
= [2 tan A/(1 - tan2 A)] x cot2 A
= tan 2A cot2 A
參考: 原創答案
2011-02-28 4:48 pm
Sol
tan2A+2cotA
=1/cot2A + cot^2A－1/cot2A
=cot^2A/cot2A
=cot^2A*tan2A
tan2A+2cotA
=1/cot2A + cot^2A－1/cot2A
=cot^2A/cot2A
=cot^2A*tan2A
收錄日期: 2021-04-20 00:09:47
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110228000051KK00245