How Does the Solution of y' = 1/(1+x^2+y^2) Behave as x Approaches Infinity?

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I have this eq.:
y'=\frac{1}{(1+x^2+y^2)}
I'm able to show that it has a unique solution for -\infty<x<\infty, and that the solution is an odd funktion.
What can I say about the limit of the solution as x grows towards infinity?
 
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For ALL x, you have:
0\leq{y'}\leq\frac{1}{1+x^{2}}

How does this help you?
 
Right! That means, y\leq{\arctan{x}}, therefor the limit of y is \leq{\pi/2}.
Thanks. I appreciate the help. :)
 
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