multivariable calculus
Quadric Surfaces
$$\\ {x^2 \over a^2} + {y^2 \over b^2} + {z^2 \over c^2} = 1$$
Green's Theorem
$$\small \oint_C Pdx + Qdy = \iint_D \frac{\partial Q}{\partial x} - \frac{\partial P}{\partial y} dA$$
Stokes' Theorem
$$\int_C \vec{F} \cdot d\vec{r} = \iint_S \nabla \times \vec{F} \cdot d\vec{S}$$