(10 points) Let A(t) = [6sin(t) 2 cos(t)] . 6 sin(t) 2 cos(t) a. Find the values of t such that A(t) is not invertible. You may use k to denote any possible integer in your answer (e.g., if the answer is all integer multiples of 5, you would enter 5k, where k is any integer). A(t) is not invertible when t = , where k is any integer. b. Find a formula for A'1(t) for the values of t for which A(t) is invertible. A-1(t) =