# Derivatives of common functions

3 videos
We told you about the derivatives of many functions, but you might want proof that what we told you is actually true. That's what this tutorial tries to do!

### Proof: d/dx(ln x) = 1/x

VIDEO 9:52 minutes
Taking the derivative of ln x

### Proof: d/dx(e^x) = e^x

VIDEO 4:40 minutes
Proof that the derivative of e^x is e^x.

### Proofs of derivatives of ln(x) and e^x

VIDEO 12:27 minutes
Doing both proofs in the same video to clarify any misconceptions that the original proof was "circular".