Areas and distances

[Poptart]

I'm working on my homework and can't figure out any of these formulas. None of it makes sense to me. I bought "The complete idiot's guide to calculus" and that isn't even helping for this section. So I need help on getting started with how to find the area under a curve, like all three formulas, for right side, left side, and midpoint. If anyone can make it make any sense to me, I think I can get the rest on my own.

 

[mammothrob]

your talking about a pretty broad topic... need to be a little more specific.
Think about talking to your professor.

 

[Poptart]

The proffessor doesn't speak slow enough and they usually just read straight from the book which doesn't help at all. The problem is 1. (a) By reading values from the given graph of f, use five rectangeles to find a lower estimate and an upper estimate for the area under the given graph of f from x = 0 to x = 10. In each case sketch the rectangles that you use. It shows a picture of the graph, but I need to know, in plain and simple english the formulas for finding the upper and lower estimates.