# Differential equation problem in Maple

I have differential equation $x\cdot\sqrt{4+y^2}\,dx + y\cdot\sqrt{1+x^2}\,dy = 0$, which is simple to solve on paper, but I have problem solving it with Maple (I use 10th, tried on 14th also). When applying dsolve it complains that it is not ODE. Any suggestions? Thank you in advance

-
Did you try dividing through by $dx$? This will eliminate $dx$ and replace $dy$ with $y'$. – Yuval Filmus Mar 8 '11 at 9:12
I believe the command you are looking for is "dsolve(x*sqrt(4+y(x)^2)+y(x)*sqrt(1+x^2)*diff(y(x),x), y(x))" – Fabian Mar 8 '11 at 9:17
@Fabian Could post as an answer. Because it is perfectly working solution. Thank you. – Kukmedis Mar 8 '11 at 9:25

dsolve(x*sqrt(4+y(x)^2)+y(x)*sqrt(1+x^2)*diff(y(x),x), y(x)).
It looks better if you include code in backticks (code): dsolve(x*sqrt(4+y(x)^2)+y(x)*sqrt(1+x^2)*diff(y(x),x), y(x)) – t.b. Mar 8 '11 at 9:38