The 82, 83, 85 all have maximum and minimum caculating features. These are very nice to have in algebra classes, because you don't have to zoom box, zoom again, and again to find what the Y max/min is and then its corresponding X. These two programs find X and Y max and min. Pluse they look almost exactly the same and can be quite accurate. Here are the two main programs: Prgm: Maximum 0->C 2->Brow 1->Bcol ClrHome ClrStat Disp "AVAILABLE MEM" Input D ClrDraw Input PrgmC X->A Input PrgmB (A-X)/IPart (D/16)->F Lbl 1 C+1->C X+F->X Y1->{x}(C If XY Lbl 2 X-F->X If Y1<>Y *** Not equal to *** Goto 2 X->[B](1,1 Y->[B](2,1 Clrhome Disp "X,Y" Disp [B] ClrStat Prgm: Minimum 0->C 2->Brow 1->Bcol ClrHome ClrStat Dips "AVAILABLE MEM" Input D ClrDraw Input PrgmC x->A Input Prgm B (A-X)/IPart (D/16)->F Lbl 1 C+1->C X+F->X Y1-{x}(C If XY Lbl 2 X-F->X If Y1<>Y Goto 2 X->[B](1,1 Y->[B](2,1 ClrHome Disp "X,Y" Disp [B] ClrStat Here are the subprograms: PrgmB: M.SUB Line(X-1,Ymax-2,X-3,Ymax Line(X-1,Ymax-2,X-3,Ymax-4 Line(X-3,Ymax,X-3,Ymax-4 PT-On(X-2,Ymax-2 PrgmC: M.Sub Line(X+1,Ymax-2,X+3,Ymax Line(X+1,Ymax-2,X+3,Ymax-4 Line(X+3,Ymax,X+3,Ymax-4 PT-On(X+2,Ymax-2 First put something in Y1, then Zoom standard. I suggest to then Zoom Integer (8) because it makes it easier for you and doesn't affect the program. After you do that run the program. Lets say you put -.1X^2+10 into Y1, you have already zoomed 6 and 8. You then run the program. It askes for available mem. The more mem available the more accurate it can get. I suggest using one of these number, even if you have a little bit more mem then them. 2080 1040 520 260 130 65 You typed in 520 at the mem available input. The program then graphs the Y1 funtion and gives you an input. Then using the arrow keys you go the the right side of the function, You click on point X=9, Y=3. Then you get another input proceed to the left side and do the same thing. It helps if both Y's are equal so on the right side you clicked on x=9, y=3, and on the left x=-8, y=3. It is very important that you click on the right side of the function first otherwise you will be caught in a loop. It is also more accurat if the x input are also the same on both sides. I believe thats it. If you have any questions/comments about this or my other programs(Dodge the Projectiles, Draw 2, Table, Distance (2)) Please contact me at Edward4793@aol.com. Josh Cunningham