## Calculus 8th Edition

(a) $e^{ln15}=15$ (b) $ln(\frac{1}{e^{2}})=-2$
The exponential function is defined by if $e^{x}=y$ then $x =lny$. Therefore, (a) $e^{ln15}=15$ (b) $ln(\frac{1}{e^{2}})=ln(e^{-2})$ $=-2lne$ $=-2\times1$ $=-2$