# Differential equation

• December 20th 2009, 09:37 AM
dapore
Differential equation

Find the solution
• December 20th 2009, 09:47 AM
HallsofIvy
Because y itself does not appear in that equation, let z= dy/dx so the equation becomes $\frac{dz}{dx}- z^2+ 4= 0$. That's a very simple separable first order equation for z. Since z= dy/dx, integrate to find y.
• December 20th 2009, 10:08 AM
dapore
I hope to complete the solution and you thanks
• December 20th 2009, 10:38 AM
Defunkt
$\frac{dz}{dx} = z^2 - 4 = (z-2)(z+2) \Rightarrow \frac{dz}{(z-2)(z+2)} = dx$...
• December 21st 2009, 08:26 AM
dapore
You the most beautiful tribute (Clapping)
• December 21st 2009, 10:26 AM
AnonymitySquared
Quote:

Originally Posted by dapore

Find the solution

You can conver this to a first order problem using substitution $u = \frac{dy}{dx}$.