若log3(底)2=a及log3(底)5=b,以a和b表示以下算式
1.log3(底)180
2.log3(底)0.6
3.log3(底)0.18
我有數學要問 (急急急急急急急!!!) log的題目
2010-02-15 11:40 pm
回答 (4)
2010-02-15 11:55 pm
✔ 最佳答案
log3 180 = log3 9*20
=log3 9 + log3 20
=2+2log 3 2 +log3 5
=2+2a+b//
log3 0.6 = log3 3 - log 5
=1-b//
log3 0.18
=log3 0.9 -log5
=log3 9 -log5 -log2 -log5
=2-2b-a//
2010-02-19 10:49 pm
1.log3 180
=log3 (9*20)
=log3 9+log3 20
=2+log3 (4*5)
=2+2log3 2+log3 5
=2+2a+b
2.log3 0.6
= log3 (6/10)
= log3 6-log3 10
= log3 (2*3)-log3 (2*5)
= log3 3+log3 2-log3 2-log3 5
= 1-b
3. log3 0.18
= log3 18-log3 100
= log3 9+log3 2 -log3 4-log3 25
= 2+a-2a-2b
= 2-a-2b
2010-02-20 07:28:11 補充：
公式:loga M+loga N=loga MN (a不等於1 a M N 大於0)
你應推到想到-變啥吧?
loga M^N=N loga M
hope can help you!
=log3 (9*20)
=log3 9+log3 20
=2+log3 (4*5)
=2+2log3 2+log3 5
=2+2a+b
2.log3 0.6
= log3 (6/10)
= log3 6-log3 10
= log3 (2*3)-log3 (2*5)
= log3 3+log3 2-log3 2-log3 5
= 1-b
3. log3 0.18
= log3 18-log3 100
= log3 9+log3 2 -log3 4-log3 25
= 2+a-2a-2b
= 2-a-2b
2010-02-20 07:28:11 補充：
公式:loga M+loga N=loga MN (a不等於1 a M N 大於0)
你應推到想到-變啥吧?
loga M^N=N loga M
hope can help you!
參考: me, me
2010-02-16 11:41 pm
log3 180
= log3 9*20
=log3 9 + log3 20
=2+2log 3 2 +log3 5
=2+2a+b//
log3 0.6 = log3 3 - log 5
=1-b//
log3 0.18
=log3 0.9 -log5
=log3 9 -log5 -log2 -log5
=2-2b-a//
= log3 9*20
=log3 9 + log3 20
=2+2log 3 2 +log3 5
=2+2a+b//
log3 0.6 = log3 3 - log 5
=1-b//
log3 0.18
=log3 0.9 -log5
=log3 9 -log5 -log2 -log5
=2-2b-a//
收錄日期: 2021-04-28 14:31:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100215000051KK00658