1. 化簡 7 - 3sin^2@ - 3cos^2@
2. 簡化 sin^2 30 cos^2 60 tan45
三角函數問題
2007-05-24 10:02 pm
回答 (3)
2007-05-24 10:12 pm
✔ 最佳答案
1.7-3(sin a)^2-3(cos a)^2=7-3[(sin a)^2+(cos a)^2]
=7-3(1)
=4
2.[(sin 30)^2]*[(cos 60)^2]*(tan 45)
=(1/2)(1/2)[1/(開方2)]
=(開方2) /8
2007-05-26 14:05:39 補充：
唔好意思之前計錯左 - -2.[(sin 30)^2]*[(cos 60)^2]*(tan 45)=(1/4)(1/4)[1/(開方2)]=(開方2) /32
2007-05-24 10:19 pm
1. 7 - 3sin^2@ - 3cos^2@
=7 - 3(1) 因為1= cos@+sin@
=4
2. sin^2 30 cos^2 60 tan45
=0.5^4
=0.0625
=7 - 3(1) 因為1= cos@+sin@
=4
2. sin^2 30 cos^2 60 tan45
=0.5^4
=0.0625
2007-05-24 10:06 pm
溫下書就識啦
一般中三教科書都會有
sin^2 x + cos^2 x=??
sin cos tan 30 45 60係等如幾多，書都會講，你係要背架tim
一般中三教科書都會有
sin^2 x + cos^2 x=??
sin cos tan 30 45 60係等如幾多，書都會講，你係要背架tim
收錄日期: 2021-05-03 04:44:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070524000051KK02187