## Calculus 10th Edition

$-1$
$\frac{1}{e}$ becomes $e^{-1}$ through exponent rules. So, the logarithm becomes $ln(e^{-1})$. Use the rule that $log(x^{n})=nlog(x)$ to simplify the logarithm to $-ln(e).$ Finally, use the fact that $ln(e)=1$ to finally simplify the logarithm to $-1$.