1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculus 3 hw help

  1. Dec 8, 2013 #1

    VU2

    User Avatar

    let f(xy)=e^(2y)sin(pix), is f a solution to (fxy)^2 -fxx(fyy)=4pi^2 e^(4x)


    So I found fxx and fyy and fxy, which are -pi(e^(2y))sin(pix), 4sin(pix)e^(2y), 2pi(e^(2y))cos(pix) respectively,

    When i reduced everything i got e^4y(sin^2(pix))+pie^4ycos^2(pix)=pie^(4x). I am assuming it is not a solution to 4pi^2 e^(4x) because first, it doesn't add up, and second, e^(4y) is never e^(4x). Am I right, I am not sure?
     
  2. jcsd
  3. Dec 8, 2013 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    You are right that it is not a solution, but I wonder whether it's because there is a typo in the question. Maybe it should say fxy2 -fxxfyy=4pi2 e4y
     
  4. Dec 8, 2013 #3

    VU2

    User Avatar

    Yeah, me too. But the problem on the paper clearly states that. I'll bring it up to my professor. Thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Calculus 3 hw help
  1. Calculus HW Help (Replies: 7)

  2. HW help (Replies: 4)

  3. Hw help (Replies: 4)

  4. Calculus 3 (Replies: 14)

  5. Calculus 3 (Replies: 5)

Loading...