Doubt in coding a systems of ODEs with bvp4

I have a coupled ODE in terms of two variables x and y, x''''=A*x+B*y+C*y''''; y''''=D*y+E*x+F*x''''; Given with 8 boundary conditions. How will I write the function to expressed the systems of coupled ODEs to use for 'bvp4' ??? As the some of the coupling terms contains the highest derivative of the two dependent variables (i.e. y'''' in equation of x and x'''' in the equation of y)???

Answer 1

[Torsten]

x''''=A*x+B*y+C*(D*y+E*x+F*x'''') -> x''''=((A+C*E)*x+(B+C*D)*y)/(1-C*F)
y''''=D*y+E*x+F*(A*x+B*y+C*y'''') -> y''''=((E+A*F)*x+(D+B*F)*y)/(1-C*F)

Best wishes

Torsten.

[T S Singh]

Thanks Torsten, How did I miss this :-)