# 2 unit vectors dot product

1. Sep 23, 2010

### onako

I need certain stopping criterion for approximating one unit vector with another. In case there is a perfect match (after a number of iterations), the dot product of the vectors is 1. I need to know (and have a reasoning for) whether in any other case the dot product of the original unit vector and the approximation (which is also a unit vector) is less than 1.
Thanks

2. Sep 23, 2010