How to solve system of ODE equations with two variables?

I want to sovle two equations with two variables δ, Δ numerically. So I tried to use ode45 but I didnt find anyone have the problem that second order of two variables are in one equation. This is a simpified version of the equation.

M*(d^2δ/dt^2+d^2Δ/dt^2)=2δ+1

M*(d^2δ/dt^2+d^2Δ/dt^2)=2Δ+1

Does anyone know how to solve these two equations numercially?

[Davide Masiello]

Better provide the not simplified version.

[Torsten]

The left-hand sides of your equations are identical. This means also the right-hand sides have to be identical. Thus δ=Δ.

[Davide Masiello]

That's what I noticed too, hence my request for the complete set of equations. Maybe that won't be redundant.

Answer 1

[Steven Lord]

I'd probably use one of the ODE solvers with a Mass matrix. See this documentation page for one example that converts a system of three second-order differential equations into six first order equations with a mass matrix and this documentation page for a different example.

Answer 2

[Image Analyst]