How to find a normal vector from a vectorial equation?

Question

I have the following vectorial equation

• $[x,y] = [1,1]+k[2,-1]$

The question asks me to find a normal vector of this line represented by this equation. However, I only know that we can find direction vector from this equation which is [2,-1].

So how can I found the normal director?

Thanks!

Answer 1

A normal vector to that line is any orthogonal vector to $(2, -1)$. For example $(1, 2)$.