# Thread: What does this notation mean? Leibniz's notation for second derivative?

1. ## What does this notation mean? Leibniz's notation for second derivative?

Hi everyone,

I have come across the following notation and I'm not sure what it means:

I thought it meant the second derivative but I have only ever seen that denoted:

Can anyone help me out here?

Thanks, Tim.

2. It doesn't mean anything. It is probably a misprint for the second derivativel,
$\frac{d^2y}{dx^2}$

The other possibility is that it is a misprint for
$\frac{dy^2}{dx}= 2y\frac{dy}{dx}$.