Need help with some practice questions! Much appreciated.

1. Let A = [1, 2,3, 4). Which of the following is AAT? (b) [30] 2 3 4 (d) [1 4 9 16] 2 4 6 8 (a) (c) 3 9 12 16 2. Which of the following pairs of matrices can be multiplied to show that in general AB / BA? (a) A- 0 0 B - (C)A- 8 8. "-6 1 (b) A = 1 1 , B- 6 2 (d) A = 1 i. B- 6 11 2 3. If C = , which of the following is det(C)? 0 0 0 2 (a) -48 (b) -8 (c) 48 (d) 6 0 0 4. If A = 0 3 4 , which of the following is 1-1? 0 0 (a) (b) (c) 3 5. Let ve R* be a unit vector and ke R\\ {0). What is | |v x kull? (a) k (b) 0 (c) k-1 (d) 1