$-6xy^3\left(3x^2y-4xy^4-2x^2y^2\right)$

$4\sin^3\theta-2\sin\theta=0$

$e\left(0\right)$

$-2-3\left(-8\right)$

$2\cdot\left(x^2+3\right)-2x\cdot\left(x-3\right)+6\cdot\left(x^2-x-1\right)$

$e^{2x\left(2\cos\left(y\right)dx-\sin\left(y\right)dy\right)}=0$