Program:	LAGRANG2
Author:	Dave Gaebler
February 17, 1999

Variables used:A,B,N,X,Y,[A],L1,L2,L3
This program does not actually use the Lagrange Interpolation Formula, but it does find 
the coefficients of a polynomial (again, in fractional form if possible).  Given n points,
each x-coordinate must be raised to the power of n-1.  If one of the x-coordinates is 
really big, or there are a lot of points, you will probably get either an overflow error 
or a totally bogus answer.  But for (reasonably) small numbers of points with (reasonably)
small x-coordinates, it's accurate and quite fast.