TI-81 Conic Section Grapher Public Domain by Daniel Bishop http://www.ticalc.org/archives/files/authors/35/3568.html This program will graph relations of the form AX²+BXY+CY²+DX+EY+F=0. Prgm_:CONIC :Disp "X² COEF" :Input A :Disp "XY COEF" :Input B :Disp "Y² COEF" :Input C :Disp "X COEF" :Input D :Disp "Y COEF" :Input E :Disp "CONSTANT" :Input F :All-Off :"(-(BX+E)+sqrt((BX+E)²-4C(AX²+DX+F)))/2C -> Y3 :"(-(BX+E)-sqrt((BX+E)²-4C(AX²+DX+F)))/2C -> Y4 :DispGraph