# Finding unit vectors perpendicular to points.

• Sep 4th 2011, 02:59 PM
deezy
Finding unit vectors perpendicular to points.
Find unit vectors perpendicular to a = (1, 3, -1) and b = (2, 0, 1).

I understand that the cross product of two vectors will give a vector that is perpendicular to them. So I did the cross product and I have 3i - 3j - 6k.

How do I find more vectors that are perpendicular?
• Sep 4th 2011, 03:22 PM
Plato
Re: Finding unit vectors perpendicular to points.
Quote:

Originally Posted by deezy
Find unit vectors perpendicular to a = (1, 3, -1) and b = (2, 0, 1).
I understand that the cross product of two vectors will give a vector that is perpendicular to them. So I did the cross product and I have 3i - 3j - 6k.

Here are the two unit vectors:
$\pm\frac{3i-3j-6k}{\|3i-3j-6k\|}$
• Sep 4th 2011, 03:27 PM
deezy
Re: Finding unit vectors perpendicular to points.
How do you know that those vectors are perpendicular, and does 3i - 3j - 6k count?
• Sep 4th 2011, 03:38 PM
Plato
Re: Finding unit vectors perpendicular to points.
Quote:

Originally Posted by deezy
How do you know that those vectors are perpendicular, and does 3i - 3j - 6k count?