Question 4 10 marks Consider the following parameter-dependent 3 x 3 matrix, where the parameter fe R: 2 4 A(D= 1 t 2 (3) 0 3 (a) Determine the rank of the matrix A. (6 marks) (b) Determine the dimension of the null space of A, i.e. calculate dim nul(A). (2 marks) (c) Is the matrix A invertible? Justify your answer. (2 marks) Your answers to the above questions may depend on the value of the parameter t