1. The problem statement, all variables and given/known data An area is enclosed by y=1/x, the positive x-axis and x=1 and x=2. Determine the volume of the rotational body that is created around the y-axis. 2. Relevant equations The formula is pi*integrate from d to c for x^2 dx. 3. The attempt at a solution Take a look here: http://www.wolframalpha.com/input/?i=y=1/x,+y=0,+x=1,+x=2&a=*C.1-_*NonNegativeDecimalInteger- I want the rotational volume for the area that is above the the purple, below the blue and between yellow and green. So how do I find the integration "limits" d and c, and what is x^2 in this case? Okay so the integration points should be 1/x and then I enter x=1 because that is the higher one in the graph, 1/1 = 1. So the upper limit is 1. The lower should be zero, because the problem statement says that it is enclosed by the positive x-axis, y=0. But if I do this, I will also get all of it that is to the right of the green line. If I use 1/2 as my other integration limit, (x=2), there will be a missing rectangle just below. How do I do this?