M = sym_matrix_sym('m',5,5);

M(2,1) = 0;
M(1,2) = 0;

M(2,3) = 0;
M(3,2) = 0;

M(4,5) = 0;
M(5,4) = 0;

M(3,3) = M(2,2);
M(5,5) = M(4,4);

M(2,4) = M(3,5);
M(4,2) = M(5,3);

M(2,5) = -M(3,4);
M(5,2) = -M(4,3);


lambda = sym('lambda','real');

W = [zeros(3,3) zeros(3,2); zeros(2,3) eye(2)];

poly = det(M + lambda * W );

c = coeffs(poly, lambda)

c(1)
c(2)
c(3)