I can't graph on my ti-84 plus silv. edition

More than likely, you've put in a number in the xmin or xmax that is not correct. Example....you put in an xmin of 10 and an xmax of -10 which would be backwards. This could also happen in the ymin or y max.

The easiest way to fix this is to press zoom 6 which wil get you back to the default graph of xmin of -10, xmax of 10 and ymin of -10 and y max of 10.

If you can't see your graph on this screen and need to change the window, just be sure the number in the min for both x & y is smaller than the number in the max. You change your window size by pressing the window button.