Thanks for the code, its amazing!
but.... even after I pluged the real values for x (you can even check the file "math graph.pdf" in the first post to check) its still badly conditioned, and there is no graph :-(
Open this attachment to see the problem.
Edit: Guys its ok, this project took me alot of time (you have no idea, so I'll just tell the teacher that I tried, I screw it if I get a bad grade in this project, I did my best)
Thanks for the help