Predicting a Step with the Jacobian

A nonlinear layer applies the map

$f(x,\ y) = \big(x^2 y,\ \ 3x - y^2\big)$

You are sitting at the point $p = (2,\ 1)$ and take the small step

$\delta = \begin{bmatrix} 0.1 \\ -0.2 \end{bmatrix}$

Using the Jacobian $J$ of $f$ evaluated at $p$, what is the predicted change in the output, $J\delta$?