i need help
log3^x-log3^4=2
solve the following equation?
2009-05-22 3:11 pm
回答 (7)
2009-05-22 3:16 pm
✔ 最佳答案
Hi,log 3^x - log 3^4 = 2
log (3^x / 3^4) = 2
(3^x / 3^4) = 10²
3^x / 81 = 100
3^x = 81 * 100 = 8100
x ln 3 = ln 8100
x = ln 8100 / ln 3
x = 8.1918
Hope this helps!
J
2009-05-22 10:49 pm
log(3^x) - log(3^4) = 2
(x)log(3) = 2 + log(3^4)
(x)log(3) = 2 + 4log(3)
x = [2 + 4log(3)]/[log(3)]
x = 2/[log(3)] + [4log(3)]/[log(3)]
x = 2/[log(3)] + 4
(x)log(3) = 2 + log(3^4)
(x)log(3) = 2 + 4log(3)
x = [2 + 4log(3)]/[log(3)]
x = 2/[log(3)] + [4log(3)]/[log(3)]
x = 2/[log(3)] + 4
2009-05-22 10:20 pm
Log 3^x - Log 3^4 = 2
x Log 3 - 4 Log 3 = 2
(Log 3)(x - 4) = 2
x - 4 = 2 / Log 3
x = (2 / Log 3 ) + 4
x = 8.19
x Log 3 - 4 Log 3 = 2
(Log 3)(x - 4) = 2
x - 4 = 2 / Log 3
x = (2 / Log 3 ) + 4
x = 8.19
2009-05-22 10:20 pm
log [ 3^x / 3^4 ] = 2
3^x / 3^4 = 100--------------------( using base 10 logs )
3^x = 8100
x log 3 = log 8100
x = log 8100 / log 3
x = 8.192
3^x / 3^4 = 100--------------------( using base 10 logs )
3^x = 8100
x log 3 = log 8100
x = log 8100 / log 3
x = 8.192
2009-05-22 10:20 pm
log3^x-log3^4=2
x log(3) - 4 log(3) = 2
x log(3) = 2+4 log(3)
x = (2 + 4 log(3)) / log(3)
Substitute log(3)=0.47712125 and simplify:
x= 8.1918
x log(3) - 4 log(3) = 2
x log(3) = 2+4 log(3)
x = (2 + 4 log(3)) / log(3)
Substitute log(3)=0.47712125 and simplify:
x= 8.1918
2009-05-22 10:19 pm
OK
log3^x-log3^4=2
Log(a)-Log(b) is the same as Log(a/b)
so Log(3^x/3^4)=2
so Log(3^(x-4))=2
(x-4)(Log(3))=2
x-4=2/(Log(3)
x= 2/(log3)+4
x= 8.192 approx assuming logs to base 10
log3^x-log3^4=2
Log(a)-Log(b) is the same as Log(a/b)
so Log(3^x/3^4)=2
so Log(3^(x-4))=2
(x-4)(Log(3))=2
x-4=2/(Log(3)
x= 2/(log3)+4
x= 8.192 approx assuming logs to base 10
2009-05-22 10:17 pm
log (3^x / 3^4) = log 9
x-4 = 2
x = 6
x-4 = 2
x = 6
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https://hk.answers.yahoo.com/question/index?qid=20090522071105AAqL3h7