How do you solve lnx + ln (x-2) = 1?

1 Answer
May 5, 2016

I found: x=1+sqrt(1+e)

Explanation:

I would write it as one log (multiplying the arguments) as:
ln[x(x-2)]=1
then use the definition of log and write:
x(x-2)=e^1
x^2-2x-e=0
use the Quadratic Formula to find x:
x_(1,2)=(2+-sqrt(4+4e))/2=(2+-2sqrt(1+e))/2=1+-sqrt(1+e)
I would use the positive one only, i.e.:
x=1+sqrt(1+e)