# Second derivatives review

Review your knowledge of second derivatives.

## What are second derivatives?

The second derivative of a function is simply the derivative of the function's derivative.

Let's consider, for example, the function . Its first derivative is . To find its second derivative, , we need to differentiate . When we do this, we find that .

*Want to learn more about second derivatives? Check out this video.*

## Notation for second derivatives

We already saw Lagrange's notation for second derivative, .

Leibniz's notation for second derivative is . For example, the Leibniz notation for the second derivative of is .