Primitive of Exponential Function

Theorem

 * $\displaystyle \int e^x \ \mathrm dx = e^x + C$


 * $\displaystyle \int a^x \ \mathrm dx = \frac 1 {\ln a}a^x + C$

where $a$ is a constant and $a > 0$.

Base e
The result follows by the definition of the indefinite integral.