$$2 x \operatorname{sign}{\left(x^{2} - 4 \right)}$$
/ 2 / 2\ / 2\\
2*\4*x *DiracDelta\-4 + x / + sign\-4 + x //
$$2 \cdot \left(4 x^{2} \delta\left(x^{2} - 4\right) + \operatorname{sign}{\left(x^{2} - 4 \right)}\right)$$
/ / 2\ 2 / 2 \\
8*x*\3*DiracDelta\-4 + x / + 2*x *DiracDelta\-4 + x , 1//
$$8 x \left(2 x^{2} \delta^{\left( 1 \right)}\left( x^{2} - 4 \right) + 3 \delta\left(x^{2} - 4\right)\right)$$