# How do you find two unit vectors orthogonal to A=(1, 3, 0) B =(2, 0, 5) first vector must have positive first coordinate?

##### 1 Answer

Jul 1, 2016

#### Explanation:

Let C(a, b, c) be a vector orthogonal to A(1, 3, 0) and B(2, 0, 5).

Then,

So, a+3b=0 and 2a+5b=0. Eliminating b and c,

C becomes

So, the unit vectors in opposite directions that are orthogonal to A

and B are