Here is a fairly generic exponential function (blue) and its inverse, a logarithmic function (red). Play with the sliders and watch the graph. Notice the green and purple points; the green point is (h, k+a) and the purple point has the x and y reversed: (k+a, h) Note that these are always on their respective graph (why?). Also notice that both the exponential and log functions have asymptotes and that f and f ⁻¹ are symmetric about the y-x line.

You may want to adjust the scale. The easiest way is to select the rightmost menu, pick zoom in or zoom out, and then click on the point you want to zoom from. Or, pick the icon on the right near the top of the applet that has north/south/east/west arrows, then drag the x and y axes to your liking. In either case you will have to choose the "move" arrow on the left to play with the sliders again.

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