## Real Analysis Exchange

### On the Mixed Derivatives of a Separately Twice Differentiable Function

Volodymyr Mykhaylyuk

#### Abstract

We prove that a function $f(x,y)$ of real variables defined on a rectangle, having partial derivatives $f''_{xx}, f''_{yy}\in L_2([0,1]^2)$, has almost everywhere mixed derivatives $f''_{xy}$ and $f''_{yx}$.

#### Article information

Source
Real Anal. Exchange, Volume 41, Number 2 (2016), 293-306.

Dates
First available in Project Euclid: 30 March 2017