This is a question from my calculus 3 class.

"Find two unit vectors in 2-space that are perpendicular to the line y = -5x + 1"

I have to do this without a dot product or any matrices. And so I'm lost as to what I have to do. Where do I begin is what I'm asking? I'm thinking I maybe have to make an initial vector along the line and then go from there? It's the rotation part that's tripping me up though.