262 PRACTICE EXAM ~ AB-1 16. If f(x) = vx-1, then the average value of f over the interval I S x $5 is (A) - (B) ( D ) w 100 NI - (E) 16 y = f' ( x ) -3 2 Questions 17-19 refer to the graph of y = f'(x), the derivative of f, shown above. The graph consists of five line segments, two of which are horizontal. 17. Atx = 1, fhas a (A) point of discontinuity (B) point of inflection (C) point of nondifferentiability D) local maximum E) local minimum 18. Over the interval -4 0, which of the following could be the graph of (A) (B) (c) (D) (E) 1 1 . If [en de = k , then [xeminutes ) dx = ( A ) - 4 (B) - alt ( D ) (E) 12. An object moves in a straight line with acceleration a() = 1' fusec'. If the initial velocity of the object is -72 fusec, at what time / does the object change direction? (A) 1=16 (B) 1=6 (C) 1=6V2 (D) 1 =36 (E) Never 13. What is the .x-coordinate of the point of inflection of the graph of 1=x + 3x - 45x + 81? ( A ) - 9 (B) -5 (C) -1 (D) 1 (E) 3 14. Which of the following functions satisfies 0