Line

Vector Equation

$$l(t)=\underset{\text{Position vector on line}}{\underbrace{\overrightarrow{OP}}}+t\underset{\text{Vector || line}}{\underbrace{\vec{v}}},t\in \mathbb{R}$$

Warning

Must include domain of variable, in this case "$t\in \mathbb{R}$"

Here $P$ is a point on the line in question, and $\overrightarrow{OP}$ is used to denote a position vector from the origin to point $P$