# Need help getting started...

• June 28th 2010, 04:00 PM
Xplorer
Need help getting started...
Hey guys I hope you can help me out with these two.

http://i551.photobucket.com/albums/i...Untitled-6.png

I think the first one is separable but I can't see how to isolate the variables. It's not exact nor can it be made exact by an integrating factor, at least I don't think it can be.

The second one I need to get in terms of y/x (dy/dx = f(y/x)) to use the z substitution method. That root xy has got me stuck.

Any help is much appreciated! Thanks!

-Tony
• June 28th 2010, 04:22 PM
pickslides

Recall $\sqrt{xy} =\sqrt{x}\sqrt{y}$
• June 28th 2010, 04:38 PM
Xplorer
If you have [IMG] code on, it will be.

But here is the direct link.
http://i551.photobucket.com/albums/i...Untitled-6.png

I got the second one now, thank you! I'm still unsure about the first one.

-Tony
• June 28th 2010, 05:08 PM
mr fantastic
Quote:

Originally Posted by Xplorer
Hey guys I hope you can help me out with these two.

http://i551.photobucket.com/albums/i...Untitled-6.png

I think the first one is separable but I can't see how to isolate the variables. It's not exact nor can it be made exact by an integrating factor, at least I don't think it can be.

The second one I need to get in terms of y/x (dy/dx = f(y/x)) to use the z substitution method. That root xy has got me stuck.

Any help is much appreciated! Thanks!

-Tony

The right hand side of your first one can be written $\frac{x (y + 3) - (y + 3)}{x (y - 2) + 4 (y - 2)}$, it should now be clear how to continue.
• June 28th 2010, 05:53 PM
Xplorer
Quote:

Originally Posted by mr fantastic
The right hand side of your first one can be written $\frac{x (y + 3) - (y + 3)}{x (y - 2) + 4 (y - 2)}$, it should now be clear how to continue.

Thats the ticket!

Thank You!!

-Tony