$-my\tan(3x^{2})+4xy+x^{2}-2y^{2}$

$\frac{2\left(-9mxy\left(\sin(x^{2})\right)^{2}\left(\cos(x^{2})\right)^{4}-9mxy\left(\cos(x^{2})\right)^{2}\left(\sin(x^{2})\right)^{4}-3mxy\left(\sin(x^{2})\right)^{6}-3mxy\left(\cos(x^{2})\right)^{6}+x\left(\cos(x^{2})\right)^{6}+9x\left(\cos(x^{2})\right)^{2}\left(\sin(x^{2})\right)^{4}+18y\left(\cos(x^{2})\right)^{2}\left(\sin(x^{2})\right)^{4}-6x\left(\sin(x^{2})\right)^{2}\left(\cos(x^{2})\right)^{4}-12y\left(\sin(x^{2})\right)^{2}\left(\cos(x^{2})\right)^{4}+2y\left(\cos(x^{2})\right)^{6}\right)}{\left(\cos(x^{2})\left(\left(\cos(x^{2})\right)^{2}-3\left(\sin(x^{2})\right)^{2}\right)\right)^{2}}$