# Derivative with natural logarithm

• November 5th 2009, 03:56 PM
s3a
Derivative with natural logarithm

y = ln(e^(-x) + xe^(-x))

Any help would be greatly appreciated!
• November 5th 2009, 04:01 PM
skeeter
Quote:

Originally Posted by s3a

y = ln(e^(-x) + xe^(-x))

Any help would be greatly appreciated!

$y = \ln[e^{-x}(1 + x)] = \ln(e^{-x}) + \ln(1+x) = -x + \ln(1+x)$

now take the derivative ...