B) find intervals on which the function is concave up or concave down. 1. concave up on (−[infinity], −1) and on (0, [infinity]), concave down on (−1, 0) 2. concave down on (−[infinity], 3), concave up on (3, [infinity]) 3. concave down on (−[infinity], −1), concave up on (−1, 0) and on (2, [infinity]) 4. none of these 5. concave down on (−3, [infinity]) 6. concave up on (−[infinity], −1