2022c Problem 2. Let f(x) = x3 + a + c + 1. In this question, any derivatives that you use must be calculated using the definition of the derivative. 1. What is the largest open interval on which f(x) is increasing? (An open interval is an interval of the form (a, b), where a, b are real numbers or the symbols too.) 2. Is f(x) invertible? 3. What is the largest open interval on which f(r) is concave down? P