Line Integrals Across Line Segment

Hello all,

I have a problem where I need to parametrize a line segment in order to evaluate a line integral, but I don't know how to do that. The problem is as follows:

"Evaluate , where is the line segment joining to ."

The book has a small example about the parametrization of line segments, but I can't follow it. Can anyone give a blow-by-blow description of how to use the equation: where ?

I understand that and are just the two points, initial and final, but how do you plug them into the previous formula to get and ?

Thanks for your consideration,

Austin Martin