求救 solve log √x+1 = log (2x)
回答 (2)
2012-10-16 7:17 am
✔ 最佳答案
log √x + 1 = log (2x)1/2 log x + 1 = log 2 + log x
1/2 log x = 1 - log 2
log x = 2 (1 - log 2)
x = 10 ^ (2 - 2 log 2)
x = 10 ^ 2 / [10 ^ log (2 ^ 2)]
x = 100 / 4
x = 25
2012-10-16 2:54 pm
log (sqrt x) + 1 = log (2x)
log (sqrt x) + log 10 = log (2x)
log (10 sqrt x) = log 2x
10 sqrt x = 2x
100 x = 4x^2
4x(x - 25) = 0
x = 0 (rej) or 25.
log (sqrt x) + log 10 = log (2x)
log (10 sqrt x) = log 2x
10 sqrt x = 2x
100 x = 4x^2
4x(x - 25) = 0
x = 0 (rej) or 25.
收錄日期: 2021-04-25 22:39:31
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