The differential equation (1) then has the form
dy
dx  = h (y) g(x) (2)
If h(y) ≠ 0, separating the variables, (2) can be rewritten as
1
( )
h y  dy = g(x) dx (3)
Integrating both sides of (3), we get
1
( ) dy
∫h y
=
( )
∫g x dx