# Identifying equation type...

• Feb 11th 2010, 08:03 AM
snaes
Identifying equation type...
Hi, I need help identifying what type of differential equation the following are. Once I know the type, I'll be able to solve them. Also, if the equations are not exact as given, we arent supposed to find the integrationg factor. Thanks!

Should be one of the following types: Seperable, Homogeneous, Linear, Bernoulli, and/or Exact.

$(2x^2y)dx+(e^{x^3+2y^3})dy=0$ ...Solved by chisigma!
As given this is not exact, but I cannot get it to fit any other types.

$(x)dx-(x^2y+y^3)dy=0$ ...yet to be solved
Also, not exact, but I cannot get this into a different form.
• Feb 11th 2010, 08:13 AM
chisigma
With simple steps we obtain...

$2\cdot x^{2} \cdot e^{-x^{3}}\cdot dx= -\frac{e^{2y^{3}}}{y}\cdot dy$ (1)

... so that the DE is separable...

Kind regards

$\chi$ $\sigma$
• Feb 11th 2010, 08:38 AM
snaes
Quote:

Originally Posted by chisigma
... so that the DE is separable...
$\chi$ $\sigma$

Thanks! I forgot that $e^{x+y}=e^{x} e^{y}$

NOTE* Still need help on one remaining differential equation:
$
(x)dx-(x^2y+y^3)dy=0
$