Since I’m not very good at imaging graphs. I would try to plot its inverse first. Then plot the real function itself. The inverse of this function is g(x) = (1/2)^(x/3) which is relatively easier to plot. We know when x = 0, g(x) = 1. We also know that g(x) will never reaches zero as it is an exponential function. If you want more points to be associated with x and g(x). Then just plug in any values for x. Then, it is just the matter of swapping the value of x and g(x) as we know that for any inverse function (if it’s one to one) that the input of f(x) becomes the output of g(x) and vice versa. There you go! If you want a sketch for f(x) then just reflect the graph with respect to the line x=y.