Question

1. Suppose that A is a 3 x 4 matrix B is a 4x6 matrix, C is a 4x3 matrix and D is a 3 x 6 matrix. Consider the following: (1)(C+AT), (2) DDTC, (3) DBT(C-24"), (4) (AB-D)B",(5) (A" +3C)D (6) ACTDT-2C. Which of the following is true? (a) All six of these are defined. (b) None of these six are defined. (c) (1), (2), (3), (4) and (5) are defined; (6) is not. (d) (1), (3) and (4) are defined; (2), (5) and (6) are not defined. (e) None of the above