(10 points) Given a square matrix A = (aij) j=1, let us define its Gershgorin disks for i = 1, n by: " D = Di = { = C |= n z = C: zai lal j=1,ji These are disks in the complex plane C, which are centered at the diagonal entries ai, and whose radius is the sum of the absolute values of the off-diagonal entries in the i-th row. (1). Draw a picture (on the same plane) of the Gershgorin disks D, D2, D3 for the matrix 2 1 1 A = = 1 2 1 1 2 3 (2). Without computing the eigenvalues of the matrix, tell whether the matrix given in part (1) could have an eigenvalue greater than 6, or less than zero, based on your picture.