1. #8, #15 on p. 72-73. Hint: A\y.

2. #14 on p.234. (take epsilon = 10^(-10))  Hint: orth(A), or QR.

3. Verify Example 5.84 on p.239. Hint: hilb(6) is the 6x6 Hilbert matrix.

4. Use Example 5.83 to check which QR decomposition Matlab uses, i.e., QR or Q_0R_0 or neither.