Logarithm problem, teach me how to fo, thanks?
回答 (1)
2019-01-12 2:36 pm
✔ 最佳答案
(a)y=ab^x
log3(y)=log3(ab^x)
=log3(a)+log3(b^x) [log(ab)=log(a)+log(b)]
=log3(a)+x*log3(b) [log(a^2)=2*log(a)]
(b)
when log3(y)=4 , x=0
4=log3(a)+0*log3(b)
=log3(a)
a=81
when x=2 , log3(y)=0
0=log3(a)+2*log3(b)
=4+2*log3(b)
-2=log3(b)
b=1/9
收錄日期: 2021-04-24 01:14:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20190112060033AAm0rAV