Consider the following MATLAB commands

$>[x,Y]=$ meshgrid $(-3$:$0\mathrm{.}2$:$3,-3$:$0\mathrm{.}2$:$3)$;

$>S=x{*}^{{?}^{?}}3-2^{**}Y*(2)$;

$>>L=\sqrt[\phantom{2}]{1+S.{?}^{{?}^{?}}2}$;