# initial value problem help!

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• April 28th 2009, 08:27 PM
TshingY
initial value problem help!
http://www.mathhelpforum.com/math-he...8&d=1240978812

I can't seem to solve this problem. First I use U substitution to get

u * du/dy + 2 * u^2 / (y+1) = u^(1/2) / (y + 1)^3

This is as far as I got. I can't get it to where I can separate the variables. Could someone show me how to get it to where I can separate the variables?
• April 29th 2009, 04:19 AM
Jester
Quote:

Originally Posted by TshingY
http://www.mathhelpforum.com/math-he...8&d=1240978812

I can't seem to solve this problem. First I use U substitution to get

u * du/dy + 2 * u^2 / (y+1) = u^(1/2) / (y + 1)^3

This is as far as I got. I can't get it to where I can separate the variables. Could someone show me how to get it to where I can separate the variables?

If you divide your u equation by u

$
\frac{du}{dy} + \frac{2 u}{y+1} = \frac{1}{(1+y)^3} \cdot \frac{1}{u^{1/2}}
$
this equation is Bernoulii.