3. Consider the following matrix: 6 -12 22 8 2 6 A= -8 20 161 I
a. Verify that A is diagonalizable. Then, find the matrix P that diagonalizes A, and next determine the diagonal matrix P-¹AP = D.
b. Verify that P-¹AP = D by showing that AP = PD.
c. By applying diagonalization, compute A³. You may use the above results.