How to solve a coupled system of differential equations with two derivatives in one equation?

Hello,

I need to solve two differential equations which one of them include two first derivatives of the two dependent variables of the problem. The equations are of the form:

1. d(xy)/dt=x+yx

2. dy/dt=yx

Which solver would be suitable for that mission? and How should it be implemented?

Thanks, Regards

[MA]

do you mean dx/dt=x ???

Answer 1

[Roger Stafford]

I think the easiest way would be to solve for dx/dt and then use any of the numerical ode functions:

dx/dt = x/y+x-x^2
dy/dt = x*y

However, if you prefer, you can use 'ode15i' which handles implicit equations of the form you have here.

Also you might try 'dsolve' for a symbolic solution.