Solving a non linear ODE with Matlab ode functions

I need to solve a non linear ODE. I want to use one of the ODE matlab functions if possible. However the problem is that it is not possible for me to convert it to a first order differential equation. The differential equation that I want to solve contains terms of this type: (y")^2*x^2+2*y*y"+(y')^2. As you can see the higher exponential is in the higher order term of the equation. Any way to solve this type of equations?

[RahulTandon]

Use solve() the solve the equations algeabraically. Get the solutions to teh quadratic equations and then solve using ODExx for nth order diff equations!! Send copy of teh actual problem. if you can.

Answer 1

[Roger Stafford]

Try using 'ode15i' which can use implicit differential equations. In your example you would presumably have the two components in your function handle:

 (y'(2))^2*t^2+2*y(1)*y'(2)+(y(2))^2 = 0
 y'(1)-y(2) = 0

Answer 2

[Iván]

you can define a system of equations like:

y'(2)= y(1);
y'(3)= y(2);

so that

y'(3)=y''(1);

in this way you can go from your equation to a ordinary diferential equation system and use any of the matlab ode solvers.

[Otoniel Diaz]

Thanks for the answer, it works well for a "simple" non linear equation in which the higher derivative can be solved but in the problem I'm facing it is not posible to solve the equation for the higher derivative.