As a start, skip the math coprocessor and use lookup tables. See these for ideas:

http://www.picbasic.co.uk/forum/showthread.php?t=3708
and
http://list.picbasic.com/forum/messa...tml?1142608044
and
http://www.picbasic.co.uk/forum/show...ghlight=arctan
and
http://www.picbasic.co.uk/forum/show...ghlight=Taylor
and
http://www.picbasic.co.uk/forum/show...ghlight=lookup

Good Luck,

Paul Borgmeier
Salt Lake City, Utah
USA