Graphing Inverse Functions on TI89

On our calculators it's not possible to computer the inverse of an inverse in any reasonably simple way, however you actually can draw it on top of another graph if you wanted to see what it looked like. So go to the Y= screen and enter in x^2 for y1, then go to Graph, and hit 2nd+F6>3 (DrawInv). This will take you to the home screen and after the DrawInv part type in y1(x). It should look like "DrawInv y1(x)" and you can then hit enter. It will then take you to the graph screen again, and show you the original graph and its inverse. Note that you cannot actually do any math with this inverse graph, and it serves merely as a visual reference.