\[f(x)=e^x\] \[f'(x)=e^x\] \[f''(x)=e^x\]
\[e^x = 1 + x + \frac{x^2}{2!} + \frac{x^3}{3!} +...\] \[e^x = \sum_{n=0}^{\infty} \frac{x^n}{n!} \]