計下列各式的值
18.(c) 1-log5/log 3開方4(個3係開方上方)............... 答案:3/2
19.(a) log (samll2係下方 ) (8開方2) ................答案:7/2
21.簡化 log(100y)/1+log開方y .........................答案:2
23.若 log(個3係開方上方)開方x=12.下列各式的值
(a) log(10x).........................答案:37
(b)logx^2...........................答案:72
急急急.....對數函數 log! 3
2011-01-25 2:33 am
回答 (1)
2011-01-25 3:22 am
✔ 最佳答案
1. (1 - log 5)/log (cube root of 4) = (log 10 - log 5)/[(log 4)/(1/3)]= 3[log(10/5)]/(log 4) = (3 log 2)/(2 log 2) = 3/2.
2. log (2)^(1/8) to the base 2 = 1/8 log 2 to the base 2 = 1/8.
3. log 100y /[1 + log y^(1/2)] = (log 100 + log y)/[1 + 1/2 log y]
= (2 + log y)/[(2 + log y)/2] = 2.
4. log x^(1/3) = 12
1/3 log x = 12
log x = 36.
(a) log (10x) = log 10 + log x = 1 + 36 = 37.
(b) log x^2 = 2 log x = 2(36) = 72.
收錄日期: 2021-04-25 22:38:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110124000051KK00864