1. tan60 / tan30
2. sin30/cos30
3. sin^2 45/ tan45
4. cos60/(tan45-sin30)^2
**詳細列式
三角比 (中三)
2009-03-08 3:14 am
回答 (2)
2009-03-08 5:49 am
2009-03-08 3:32 am
tan60/tan30
=sqroot3/ (1/sqroot3)
=3
sin30/cos30
=tan30
=1/sqroot3
sin^2 45/ tan45
=sin^2 45/ (sin45/cos45)
=sin45cos45
=(sqroot2/2)^2
=2/4
=1/2
cos60/(tan45-sin30)^2
=(1/2) / (1/(1/2))^2
=(1/2)/(1/4)
=2
=sqroot3/ (1/sqroot3)
=3
sin30/cos30
=tan30
=1/sqroot3
sin^2 45/ tan45
=sin^2 45/ (sin45/cos45)
=sin45cos45
=(sqroot2/2)^2
=2/4
=1/2
cos60/(tan45-sin30)^2
=(1/2) / (1/(1/2))^2
=(1/2)/(1/4)
=2
收錄日期: 2021-04-23 20:39:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090307000051KK01650