$-xy\tan(2x^{2})+x^{2}-y^{2}+4y$

$\frac{-4yx^{2}\left(\sin(x^{2})\right)^{4}-4yx^{2}\left(\cos(x^{2})\right)^{4}-2y\left(x\sin(2x^{2})\right)^{2}+2y\cos(x^{2})\left(\sin(x^{2})\right)^{3}-2y\sin(x^{2})\left(\cos(x^{2})\right)^{3}+2x\left(\sin(x^{2})\right)^{4}+2x\left(\cos(x^{2})\right)^{4}-x\left(\sin(2x^{2})\right)^{2}}{\left(\cos(2x^{2})\right)^{2}}$