Solve the following equation
回答 (4)
2012-10-12 5:41 pm
✔ 最佳答案
log5(x - 30)^2 = 4.9==> (x - 30)^2 = 5^4.9
==> x - 30 = 5^2.45
==> x - 30 = 51.58 (corr. To 2dp)
==> x = 81.58
2012-10-12 10:39 pm
not sure if LOG base 5 or LOG_(10) 5(x-30)^2
2012-10-12 9:53 pm
Solve the following equation
log[5(x－30)^2]=4.9
Sol
log[5(x－30)^2]=4.9
5(x－30)^2=10^4.9
5(x－30)^2=10*10^3.9
(x－30)^2=2*10^3.9
x－30=+/-2^(1/2)*10^(1.95)
x=30+/-2^(1/2)*10^(1.95)
log[5(x－30)^2]=4.9
Sol
log[5(x－30)^2]=4.9
5(x－30)^2=10^4.9
5(x－30)^2=10*10^3.9
(x－30)^2=2*10^3.9
x－30=+/-2^(1/2)*10^(1.95)
x=30+/-2^(1/2)*10^(1.95)
2012-10-12 3:55 pm
Answer: 156.0419164
Solution:
log 5(x - 30)² = 4.9
log 5 + log (x - 30)² = 4.9
log 5 + 2 log (x - 30) = 4.9
2 log (x - 30) = 4.9 - log 5
log (x - 30) = (4.9 - log 5) / 2
x - 30 = 10 ^ [(4.9 - log 5) / 2]
x = 10 ^ [(4.9 - log 5) / 2] + 30
x = 156.0419164
Solution:
log 5(x - 30)² = 4.9
log 5 + log (x - 30)² = 4.9
log 5 + 2 log (x - 30) = 4.9
2 log (x - 30) = 4.9 - log 5
log (x - 30) = (4.9 - log 5) / 2
x - 30 = 10 ^ [(4.9 - log 5) / 2]
x = 10 ^ [(4.9 - log 5) / 2] + 30
x = 156.0419164
參考: knowledge
收錄日期: 2021-04-28 14:22:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121012000051KK00036