# Thread: Vectors - Equations of Lines

1. ## Vectors - Equations of Lines

A line goes through the points (9,2) and (3,4). Determine its vector equation.

How do you find the direction vector in this question? I forgot how to do this problem and my notes in my locker.

2. Originally Posted by Macleef
A line goes through the points (9,2) and (3,4). Determine its vector equation.

How do you find the direction vector in this question? I forgot how to do this problem and my notes in my locker.

$v=\underbrace{9 \vec i + 2 \vec j}_{head}-\underbrace{(3 \vec i + 4 \vec j)}_{tail}=6 \vec i -2 \vec j$

$r(t)=r_0+tv \iff r(t)=9 \vec i + 2 \vec j +t(6 \vec i -2 \vec j)=(9+6t)\vec i +(2-2t)\vec j$