Believe it or now...but there is a function called xyline on ALL of the calcs except ti-80, and ti-81! The xyline function on the TI-82 is in a VERY out- of-the-ordinary place, but it is there nonetheless, you may spend hours looking for it...but trust me! It's there!!! (That's why I hate ti-82s and 83s, you have to hunt the menus for a function, I prefer to just type them in!)