Warning: Unable to find symbolic solution.

clc;

clear ;

syms y(x)

num= 4*atan(x)*sqrt(y*(1+x^2)) + 2*x*y;

D= 1+x^2;

u=num/D;

ode = diff(y) + u ;

ysol(x) = dsolve(ode)

[khoi phan]

Warning: Unable to find symbolic solution.

> In dsolve (line 209)

In untitled (line 9)

ysol(x) =

[ empty sym ]

[Bjorn Gustavsson]

Not all differential equations have symbolic solutions. This one looks "quite nonlinear" and you might find some clever trick to convert it to something simple, might here means something like "if this problem is designed to have a clever series of transformations you might find those". Try with numerical solutions, try to plot the ode-vectorfield for insights into what solutions look like.