已知5=10^x 及6=10^y
a 試以x和y表示log3
b 由此,試以x和y 表示log90
請列出步驟.謝謝
數學 對數問題
2015-04-07 11:38 pm
回答 (2)
2015-04-07 11:58 pm
✔ 最佳答案
5=10^x
log5=x log10
x=log5
6=10^y
log6=y log10
y=log6
log3
=log(6*5/10)
=log6+log5-log10
=x+y-1
log90
=log(3*3*10)
=2log3+log10
=2(x+y-1)+1
=2x+2y-1
2015-04-09 3:10 am
5=10^x
x=log5
6=10^y
y=log6
a
log 3
=log(30/10)
=log 5+log 6 -log 10
=x+y-1
b
log90
=log(3*3*10)
=2 log 3 +log 10
=2(x+y-1)+1
=2x+2y-2+1
=2x+2y-1
x=log5
6=10^y
y=log6
a
log 3
=log(30/10)
=log 5+log 6 -log 10
=x+y-1
b
log90
=log(3*3*10)
=2 log 3 +log 10
=2(x+y-1)+1
=2x+2y-2+1
=2x+2y-1
收錄日期: 2021-04-15 18:59:11
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20150407000051KK00061