ODE problem: 3x^2 y dx + (x^3 + 2y)dy = 0

[brad sue]

I have two ODE with which I cannot to slove;

3x²ydx+(x³+2y)dy=0

I tried to change of variable y=v*x, but I still cannot find a way to solve it.

the second is:

(e^xsin(y)-2ysin(x))dx+(e^xcos(y)+2cos(x))dx=0

here I have no idea


thank you
B

 

[quasar987]

They are exact diff equ. Have you not seen how to solve such ode's?

 

[Hurkyl]

Surely you know other techniques for solving ODE? This problem is tailor-made for one of them.