I'm looking for an easier way to find the x vaules for a given y value on a ti83. Right now I find them by graphing the function, tracing and zooming to the y value on either side of the parabola to get the approximate x value. I check this by going to "calc", selecting value and entering the approximate x value from the graph. This must then be repeated for the other side of the parabola. Is there an easier way?