Solve 4xy dx + (x² + 1) dy = 0

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Dusty912
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Homework Statement


Solve each of the following differential equations:
4xydx + (x2 +1)dy=0

Homework Equations


None

The Attempt at a Solution


4xydx + (x2 +1)dy=0
(x2 +1)dy=-4xydx
dy/y=-(4xdx)/(x2 +1)
∫dy/y=∫-(4xdx)/(x2 +1)
ln|y|=-2ln|x2+1| +C

used u-sub on last step fo u=x2 +1
 
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Dusty912 said:

Homework Statement


Solve each of the following differential equations:
4xydx + (x2 +1)dy=0

Homework Equations


None

The Attempt at a Solution


4xydx + (x2 +1)dy=0
(x2 +1)dy=-4xydx
dy/y=-(4xdx)/(x2 +1)
∫dy/y=∫-(4xdx)/(x2 +1)
ln|y|=-2ln|x2+1| +C

used u-sub on last step fo u=x2 +1
Do you have a question?
Your work looks fine to me, but you need to take it one step further and solve for y as a function of x.

After that, check your solution by verifying that it satisifies the original DE.