Hi Brian,

re:
> How to convert ax + by + c = 0 into a MoI line segment???

See page 10 "Conversion from Implicit to Parametric Form".

When you have it in parametric form you can get 2 points on the line by evaluating the parametric form at t = 0 and t = 1.

Slope intercept form is usually avoided because it has difficulty with vertical lines.


> I think r + ve means radius with a positive value. (ve meaning value???)
> On second thought, I think that r + ve, means use the positive version of radius. (ve meaning version)

I think the ve is "vector expression".

Anyway the thing that's really good about this book is that usually you don't have to translate from math notation into code, it also gives code.

So in this case "Finding a tangent may be coded:" at the bottom of page 34.

- Michael