Google Answers Logo
View Question
Q: Volume of Revolution Problem ( No Answer,   2 Comments )
Subject: Volume of Revolution Problem
Category: Science > Math
Asked by: jeremit-ga
List Price: $25.00
Posted: 25 Sep 2006 15:18 PDT
Expires: 26 Sep 2006 09:20 PDT
Question ID: 768353
The region is bounded by the curves y=cosx, y=e^-3\2x, x=o and is
revolved about the x-axis. The first point at which the curves
intersect in the first quadrant is revolved about the x-axis.

Here is the graph setup that I derived from the given information:

I can see that this has to be solved using the washer method due to
the hole that would result in the the equation for the
washer method is:

and the values for the definite integral are found by taking the x
values where the two graphs intersect.

I was wondering if I this was the correct setup to solve the equation:

I wasn't really sure if I setup this right because it seems like the
definite integral was more complicated than it needed to be and ran
into some trouble while trying to solve it.
There is no answer at this time.

Subject: Re: Volume of Revolution Problem
From: barneca-ga on 26 Sep 2006 02:16 PDT
your setup looks correct to me.  recheck your integration; the
integral you have is not that hard to do.  break into two terms;
integral of pi*cos^2(x)dx, and integral of pi*e^(-3x)dx.  each
integral is fairly easy to do.

Subject: Re: Volume of Revolution Problem
From: jeremit-ga on 26 Sep 2006 09:05 PDT
ohhhhhhhhhhh ok. I don't know why it didn't cross my mind to break up
the integrals. Im the one who made it harder than it needed to be.

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy