# Urgent: Need help with solving differential equations

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
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:

Mark44
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.

Hmm, thats weird, try going to google

Then google: Differential Equations- Swimming in salmon