F.2 Trigonometric
回答 (2)
2008-05-30 12:03 am
✔ 最佳答案
cos^2(47)+cos^2(43)=sin^2(90-47)+cos^2(43)
=sin^2(43)+ cos^2(43)
(since sin^2 A + cos^2 A =1)
=1
2008-05-30 12:03 am
cos^2(47) + cos^2(43)
= sin^2(43) +cos^2(43)
=1
= sin^2(43) +cos^2(43)
=1
收錄日期: 2021-04-15 15:20:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080529000051KK01207