1.if 10^(x-log 5)=20,find the value of x
答:2
2.log 3 45+log 3 5<-------兩個3都係3進制
答:2
3.log 2 √8+log 2 √2<---------頭兩個2都係2進制
答:2
4.log 3 81^(1/3)-log 3 3^(1/3)<---------第一同三個3都係3進制
答:1
f.4既maths
2007-10-27 10:23 pm
回答 (2)
2007-10-27 10:32 pm
✔ 最佳答案
10^(x-log 5)=20(x-log5) log 10 = log20
x-log 5 = log 20
x = log 20+log 5
x = log (20*5) = log 100
x = 2
2. log 3 45-log 3 5 <---係咪打錯, 應該係"－" instead of "+"
= log 3 (45/5) = log 3 (9) = log 3 (3^2) = 2
3. log 2 √8+log 2 √2
=log 2 (2^(3/2)) + log 2 (2^(1/2))
=3/2 + 1/2
=2
4. .log 3 81^(1/3)-log 3 3^(1/3)
= log 3 [3^(4/3)] - log 3 [3^(1/3)]
= 4/3 - 1/3
=1
2007-10-27 10:39 pm
1. (x-log5) log 10 = log 20
x=log 20 +log 5
x=log 100
x=2
3. log2 [2^(3/2)/2^(1/2)]
= log2 2^2
= 2
4. log3 [ 3^(4/3)/3^(1/3) ]
= log3 3^1
= 1
2007-10-27 14:40:29 補充：
佢打錯= =......唔怪得我計唔到@@
x=log 20 +log 5
x=log 100
x=2
3. log2 [2^(3/2)/2^(1/2)]
= log2 2^2
= 2
4. log3 [ 3^(4/3)/3^(1/3) ]
= log3 3^1
= 1
2007-10-27 14:40:29 補充：
佢打錯= =......唔怪得我計唔到@@
收錄日期: 2021-04-13 18:12:01
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https://hk.answers.yahoo.com/question/index?qid=20071027000051KK02248