Question: How to linearize three nonlinear equations?

Hello friends,

I have tried to linearize three nonlinear equations which are coupled in the form of:

a1*xdot(1)+a2*xdot(2)+a3*xdot(3)=f1(x1,x2,x3)+u(1)

b1*xdot(1)+b2*xdot(2)+b3*xdot(3)=f2(x1,x2,x3)+u(2)

c1*xdot(1)+c2*xdot(2)+c3*xdot(3)=f3(x1,x2,x3)

the ai, bi, ci parameters are constant parameters and x1, x2, x3 are variables (states). also, u(1) and u(2) are inputs to the system. xdot(i) is the derivative form of xi.

I would like to get a set of linear equations with symbolic parameters. (something similar to the exmaple which is solved in the help section of linearization).

The problem is that, the "linearize" command works in case of having one derivative term in the left side, but my equations are nonlinear coupled equations that can not be split!

I am wondering if you have any idea about solving this problem.

Thanks,

Hadi