A vector is a mathematical concept that denotes direction and magnitude. They're often notated using an arrow ($\vec{v}$), or with a bold, lowercase letter. (**v**).
Vectors are often denoted as a matrix with two rows: $\begin{bmatrix}1 \\2\end{bmatrix}$
# Magnitude
The magnitude of a vector is $|\vec{v}| = \sqrt{a^2 + b^2}$
# Direction
The direction of a vector is $\theta = \tan^-1(\frac{b}{a})$.
