Trrue or False

(10) An extreme value of function can only occur at a critical number. (11 If f is a continuous function on a closed interval [a, b], then f attains both max and min values on [a, b]. (12) If you averaged 30 miles/hr. during a trip then at some instant during the trip, you were travelling exactly at 30 miles/hr. (13) If f is continuous on a closed interval [a, b], then the function f is bounded (i.e., f(x) is finite for any x in [a, b]). (14) The second derivative of a function f will tell us about the "concavity" of f whether f is curving upward or downward