I'm trying to do some basic plots of Riemann Sums to demonstrate the lower sums of a function. I cannot figure out to make this work in the Mathematica (v.5.2). I was figuring the easiest way was to simply have a bar chart in the same plot of the function, but I cannot figure out how to make this work. The primary problem is that the partitions begin at -1 and I cannot get the bar chart to accept that I'm working with negative x-values. Any help would be greatly appreciated. Thank you.