Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

agentx5 Group Title

Is this correct? (+1 medal will be given) Q: Use the method of cylindrical shells to find the volume of the solid obtained by rotating the region bounded by the given curves about the x-axis. (x - 3) = (y − 7)\(^2\), x = 19 A: \(y = 7\pm \sqrt{(19)-3} = 3 or 11 \), therefore: \[\huge\int\limits_3^{11} (2 \pi)(y)(3 + (y − 7)^2) dy = \frac{2800 \pi}{3} \] Graph below:

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    • 2 years ago
    1 Attachment
  2. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    I'm doing something wrong here I believe, because the computer is going NO! *slap*

    • 2 years ago
  3. dpaInc Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    i don't see anything wrong...

    • 2 years ago
  4. dpaInc Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    that is correct...

    • 2 years ago
  5. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Hmm, it's not taking the answer though. (online homework thing, and I thought I had this section well understood)

    • 2 years ago
  6. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    http://www.wolframalpha.com/input/?i=integrate+from+3+to+11+for+2pi+y+%283+%2B+%28y+%E2%88%92+7%29^2%29+dy

    • 2 years ago
  7. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Integration checks out, is it a setup error?

    • 2 years ago
  8. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Using the disk method is a non-option here I believe

    • 2 years ago
  9. dpaInc Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    did you enter the decimal answer instead of the exact answer? it is possible to do this using the disk (washer method) but not recommended... either way, the answer should still be the same..

    • 2 years ago
  10. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    WebAssign (that's the the software provider is) allows for exact answer input (copy & paste disabled logically, but I can put it in as displayed above).

    • 2 years ago
  11. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    I've double checked it and I've x = 3 + (y − 7)^2 and the rest of the instructions I've typed them over word for word. I don't see any errors in my scratch work either

    • 2 years ago
  12. dpaInc Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    all i can say is that there is nothing with your set-up or your integral...

    • 2 years ago
  13. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    This is even one of those where you get to select the graph from multiple choice for points, and that's ok too. So what the heck WebAssign? :D

    • 2 years ago
  14. dpaInc Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    write to them saying you got the answer correct but the computer won't accept it AND ask for monetary compensation since it's their fault and not yours...:)

    • 2 years ago
  15. Eyad Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Correct ,give me my medal ... JK,give it to Dpalnc

    • 2 years ago
  16. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    HAHA!

    • 2 years ago
  17. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Maybe you all are right. I mean integration isn't that hard on this problem, and even Wolf agrees so what the heck? I tried entering it as a decimal and it slapped me down again.

    • 2 years ago
  18. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    There's not some weirdness with a discontinuity of some kind here is there? I'm giving you a cookie for your hard effort @dpalnc :D

    • 2 years ago
  19. KingGeorge Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Sorry I've just been sitting here so long, but don't you need to include the \(x=19\) in the part you're integrating as well?

    • 2 years ago
  20. KingGeorge Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I believe you should instead be integrating \[\huge\int\limits_3^{11} (2 \pi)(y)(19-(3 + (y − 7)^2)) dy \]

    • 2 years ago
  21. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Hmm, let me try that and see... :-)

    • 2 years ago
  22. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    YOU DID IT! :D Way to go @KingGeorge !!! (darn I gave out the medal earlier, I'd have given you 5 right now if I could) Hmm, now let me see if I understand why... Area between curves? y=19 is the upper layer?

    • 2 years ago
  23. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Kind of odd how it's all turned sideways because of the switch between what is normally independent and dependent

    • 2 years ago
  24. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    A(y) \(\rightarrow\) Right - Left?

    • 2 years ago
  25. agentx5 Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    @dpaInc @Eyad , he got it, FYI :-D

    • 2 years ago
  26. KingGeorge Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    It should be the right minus the left in your integrand for the shell method.

    • 2 years ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.