Question

I want to find eigenvalues of system :
" A*d^2y/dt^2 + B*dy/dt + C*y = f(t) "
A,B,C are 6*6 matrices and y is 6*1 and B and C are almost diagonal constant matrices which are not symmetric but A is a diagonal matrix. Please help me to solve this system.[/code]

matrices B & C are like as below:
C = [C1 , -C1 , 0 , 0 , 0 , 0;
-C1 , C1+C2 , -C2 , 0 , 0 , 0;
0 , -U_G*C2 , U_G*C2+C3/U_G , C3 , 0 , 0;
0 , 0 , C3*U_D/U_G , U_D*C3+C4/U_D , C4 , 0;
0 , 0 , 0 , C4/U_D , C4/U_D+C5 , -C5;
0 , 0 , 0 , 0 , -C5 , C5]