<p>Yeah I have to put the 2 outside the parenthesis...sorry</p>
<p>the calc part is so much easier for me than the no calc part... the only things i mess up are like accidentally thinking 1+2=4. also i didn't have time to finish all the no calc probs but had soo much extra time on the calc part. i think i'm just overly calculator-dependent.</p>
<p>mdtracie: It really depends on what you're revolving the object around. The easiest thing to do is to just draw it out and figure out what would give you the radius of what you're looking for. In this case we're using the Washer Method, so we obviously need the radius of the "outside" function, and then we have to subtract from that the radius of the "inside" function.</p>
<p>So you would draw the function on the interval you're interested in, draw the line you're revolving it around, and then draw the same function reflected across that line to give you an idea of what the object will look like. And then you could use all that (or actually just the line and the original function) to figure out equations for the radii you're interested in. If you try to generalize it too much you're going to get confused and possibly make mistakes; I'm not even sure if that's practical, because there are so many different cases, depending on what line you're revolving your function around and what method you have to use to solve for the volume...</p>
<p>Arco's has best explanation for revolving things.</p>
<p>Time really isn't an issue for me on any of the test. My problem is taking my time. I sometimes need to slow down and really think about the question because once I've done the question I don't go back to it unless its marked so I don't catch careless mistakes.</p>
<p>Does anyone have an understandable way to do cross sections? My teacher taught it to us but not very clearly.</p>