Category:Normal Vectors

This category contains results about Normal Vectors.
Definitions specific to this category can be found in Definitions/Normal Vectors.

Let $S$ be a surface in ordinary $3$-space.

Let $P$ be a point of $S$.

Let $\mathbf n$ be a vector whose initial point is at $P$ such that $\mathbf n$ is perpendicular to $S$ at $P$.

Then $\mathbf n$ is a normal vector to $S$ at $P$.