唔識log數．．．．．．．．．．．．．．．．．．

2007-02-19 2:42 am

試不用計算機計算,,
A) -1/2LOG625-LOG4
B) (LOG32-log64)/log128
c) (3log3-log243)/log9
d) (1.5log16-2log2)/(log36-2log3)

1.(log a^4+logb^8)/logab^2
2.(4logx^2+ 2log x^4)／ｌｏｇ　ｘ＾３

打得好亂．希望你地識睇
／姐係分線
希望你地幫我列埋步驟，等我自己理解下啦．
ｔｈｘ！！！

回答 (1)

myisland8132

2007-02-19 2:50 am

✔ 最佳答案

a
-1/2LOG625-LOG4
=4(-1/2)LOG5-2LOG2
=-2LOG5-2LOG2
=-2(LOG10-log2)-2LOG2
=-2
b
(LOG32-log64)/log128
=(5log2-6log2)/(7log2)
=-1/7
c
(3log3-log243)/log9
= (3log3-5log3)/(2log3)
=-1
d
(1.5log16-2log2)/(lo g36-2log3)
=(6log2-2log2)/(2log6-2log3)
=(6log2-2log2)/(2(log3+log2)-2log3)
=(4log2)/(2log2)
=2
1.
(log a^4+logb^8)/logab^2
=(4log a+8logb)/(loga+2logb)
=4
2.
(4logx^2+ 2log x^4)／ｌｏｇ　ｘ＾３
=(8logx+ 8log x)／(3ｌｏｇx)
16/3

2007-02-18 18:51:29 補充：
最後應是=16/3

👍 0 👎 0