Definition:Vector Quantity/Component/Z Component

Definition
Let:
 * $\mathbf a = x \mathbf i + y \mathbf j + z \mathbf k$ be a vector quantity embedded in Cartesian $3$-space $S$

where $\mathbf i$, $\mathbf j$ and $\mathbf k$ be the unit vectors in the positive directions of the $x$-axis, $y$-axis and $z$-axis respectively.

The value $z$ is known as the $z$ component of $\mathbf a$.