[4 pt] 14. Which of the following is true about a differentiable and invertible function f (x) such that f' (f -1 (x)) * 0. a. (f -1 )' (x ) = - f' (x) fi(f ( x ) ) b. (f - 1 )' ( x ) = Fi(f ( x ) ) 1 c. (f -1 )' (x ) = Fi(f-1 ( 2) ) 1 d. (f -1)' (x) = Fi(f-1(2)) f (x) [4 pt] 15. Let f (x) be a differentiable function on a closed interval with x = a being one of the endpoints of the interval. If f'(a) > 0, then: A. f could have either an absolute maximum or an absolute minimum at x = a. B. f cannot have an absolute maximum at x = a. C. f must have an absolute minimum at x = a