28. Let a = (1, 2,0) and y = (1, -3, 2). (a) Calculate || Z Il. (b) Calculate the distance between I and y. (c) Calculate i . y. (d) Calculate the angle between a and y. 29. Consider the set of vectors B = {(3, 4), (1, 2) } in R2. (a) Prove that B is a basis for R?. (b) Perform the Gram-Schmidt orthonormalization to make B an orthonormal basis for R. 30. Consider the set of vectors B = {(2, 0, 0), (1, 1, 0), (0, 1, 2) } in R3. (a) Prove that B is a basis for R3. (b) Perform the Gram-Schmidt orthonormalization to make B an orthonormal basis for R3. 31. Find the least squares regression line for the points {(1, 1), (2, 0), (4, -2) }