The math TLO is part of innerspace, so this would be more properly asked on the ismods or lavish forums. That said, the incomplete .NET development wiki http://www.lavishsoft.com/wiki/index.php/IS:.NET#C.23 explains how to get access to any TLO that you like. Poking around at the source of any wrapper should give you the same info...technically a wrapper is just doing this same footwork for you, using the mechanisms for getting at just about any LavishScript object that Lax provides.
The reason that the Math object is not wrapped in .NET is that it's horribly inefficient compared to doing the same calculation in .NET instead of calling into LavishScript to do it. If you need the distance function for example, it's a lot better to just write the couple lines of code to do it in .NET.
And that will run much, much faster than calling the LavishScript equivalent. To use the LS function that does the same thing, it's converting those numbers to strings, then back to numbers, then doing the calculation, instead of just doing a couple fairly trivial calculations. I would recommend NOT wrapping the Math TLO.
I already went with the custom implementation. My desire to use the TLO is based from a preference to encapsulate the base functionality. In this instance it wasn't very important, but habits are habits