對數方程式,求解答過程?

2016-01-03 9:01 am

回答 (2)

2016-01-03 9:07 am
✔ 最佳答案
Sol
x^(1+logx)=(10x)^3
log[x^(1+logx)]=log[(10x)^3]
log[x^(1+logx)]=log1000+logx^3
(1+logx)*logx=3+3logx
Set p=logx
(1+p)*p=3+3p
p^2-2p-3=0
(p-3)(p+1)=0
p=3 or p=-1
(1) p=3
logx=3
x=1000………….
(2) p=-1
logx=-1
x=1/10…………..
2016-01-06 10:45 am
x^(1+logx)=(10x)^3
log[x^(1+logx)]=log[(10x)^3]
log[x^(1+logx)]=log1000+logx^3
(1+logx)*logx=3+3logx
Set p=logx
(1+p)*p=3+3p
p^2-2p-3=0
(p-3)(p+1)=0
p=3 or p=-1
(1) p=3
logx=3
x=1000………….
(2) p=-1
logx=-1
x=1/10…………..


收錄日期: 2021-04-18 14:15:21
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160103010128AAPo8zC

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