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e^lnx=x

i understand why ln(e^x)=x, but not the other way around

2006-09-06 10:48:50 · 3 answers · asked by egyptsprincess07 3 in Science & Mathematics Mathematics

3 answers

Consider this: let y = ln x

Then e^y = x

If we ln both sides,
ln(e^y) = ln x
y = lnx
ln x = ln x

Thus e^ln(x) = x


Alternatively, if we define ln(x) = y, then

x = e^y (be definition of a logarithm)
x = e^ln(x) (because y = ln(x))

2006-09-06 10:57:52 · answer #1 · answered by sax7515 2 · 0 0

If you understand that ln(e^x)=x you can realize that taking the ln of the left side of [e^lnx=x] gives you [ln(e^lnx)=lnx]

2006-09-06 17:55:08 · answer #2 · answered by maegical 4 · 0 0

1_(e^x)=T so 2_ ln(e^x)=lnT so 3_ x=lnT from 1 and 3 e^lnT=T. Good luck

2006-09-06 18:22:52 · answer #3 · answered by igi_amirali 2 · 0 0

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