Name: Parabola 3 Points (Y)
Version: 1.1
Author: Nishad Phadke (nishad.phadke@hotmail.com)
Date: May 28, 2011
Tested on TI-89 HW 2.00 OS 2.09.

Documentation:
1. Type in the function name.
2. Type in the coordinates of three points para3pty(x1,y1,x2,y2,x3,y3).
3. Obtain the equation of a parabola passing through all three points that is parallel to the y-axis.