# Solving a system of nonlinear second order differential equations.

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Sina on 2 Feb 2016
Commented: Torsten on 5 Feb 2016
I have developed a set of n equations, n variables for my dynamic system. The derivatives are second and first order in terms of theta (angle) of different components of the system (basically a set of n lagranges equations). I need to solve the system using Matlab or Simulink. l_i and m_i are constants and F_x and F_z and F_y are known. The only variables are θ_i. I need to solve system (3.40) basically for all θ's (time transient response)
To simplify, I have the following equation which I need to solve for θ's
F(t,θi, θ'i, θ"i)=G(θi) (i=1,...,n)
and all n equations are coupled.
1. Can I do this so that I can get the time transient results (for all \theta)? 2. What is the best way to approach this? Hopefully to be able to animate this!? Thanks a million.

#### 1 Comment

Torsten on 5 Feb 2016
In my opinion, B*thetadot*thetadot is not defined (B*thetadot is an (nx1) vector which can not be multiplied with another (nx1) vector.)
Best wishes
Torsten.