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!

Urgent: Need help with solving differential equations

  1. Apr 17, 2010 #1

    CR9

    User Avatar

    Hi guys,

    So I have gotten my assignment for my DE class and fortunately for me, someone had already posted up the questions on the net. Here it is:

    http://www.cengage.com/math/book_con...e/Project3.pdf [Broken]

    I have posted this in the DE section, which i think is the wrong section to post in.

    Anyway I have managed to do a number of the questions as below together with the answers:

    1) sinh [-ln x] - sinh [-ln w] = y/vx : whereby v= Vr/ Vs
    2) Have yet to try
    3) From the answer i got in (1), I just substituted y= 0 and x= -w, and i get something like this: Vr/ Vs = 0 ...... and since Vr = 0 and Vs is any value greater than 0, it is proven what the question wants... Not sure though if it is right :S Please help me check...
    4) No prob with this, got it proven
    5) r= wsec θ/(sec θ + tan θ)^Vs/Vr
    6) I just dont know what values to sub in to solve it..please help
    7) No prob with this too, got it done
    8) Done, got y=2.5 Bubba survives

    So guys, I hope you all can help me figure out how to do number 6 and perhaps see if my number 3 is right?

    Thanks so much...

    Best regards
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Apr 18, 2010 #2

    Mark44

    Staff: Mentor

    The link you supplied goes to http://www.cengage.com and no further. It doesn't show the problems you mention.

    If you want help on 6 and a confirmation of your answer on 3, please post these problems and the work you have done.
     
  4. Apr 19, 2010 #3

    CR9

    User Avatar

    Hmm, thats weird, try going to google

    Then google: Differential Equations- Swimming in salmon

    Its the first link...

    Hope you guys can help. Thanks a bunch!
     
  5. Apr 19, 2010 #4

    Mark44

    Staff: Mentor

    We shouldn't have to search the internet to find your problem. If you want help, please post your problem and the work you have done.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook