# What's meant by this?

1. Dec 3, 2011

### MHD93

Let y = x^2 + 3x

and the question is Find $\frac{dy^2}{dx^2}$

then how do I understand this token? is it $\frac{d(y^2)}{d(x^2)}$
or $\frac{(dy)^2}{(dx)^2}$ = $(\frac{dy}{dx})^2$
or what ?

BTW: it's not wrong written, namely, not $\frac{d^2y}{dx^2}$

2. Dec 3, 2011

### mathman

The notation is unusual. I would guess that you let u=x2 and v=y2, and compute dv/du. Then put x and y back into the result.

Last edited: Dec 3, 2011