# Logarithm exponential, solve for x

• Dec 18th 2008, 07:02 AM
mwok
Logarithm exponential, solve for x
I don't know how to solve this.
• Dec 18th 2008, 07:23 AM
Mush
Quote:

Originally Posted by mwok
I don't know how to solve this.

Take natural logarithms of both sides, noting that:

$ln(e^{f(x)}) = f(x)$
• Dec 18th 2008, 09:00 AM
tester85
Take not lne = 1

e^1-2x = 5
lne^1-2x = ln 5 ( ln both sides )
1-2x(lne) = ln5
1-2x = ln5
2x = 1-ln5
x = 1-ln5/2