Section I - AP Calculus AB – McDermott Name_________________________________ AP CALCULUS AB Chapter 7 Review Section I: Multiple-Choice Questions A CALCULATOR SHOULD ONLY BE USED ON PROBLEMS NUMBERED 76 OR HIGHER Instructions: Section I of the AP exam contains 28 non-calculator multiple-choice questions (numbered 1-28) and 17 calculator multiple-choice questions (numbered 76-92). This review contains problems specific to the current unit, however, any topic that has been covered thus far this year is a fair question to put on any unit test (It is therefore suggested that you also look at past Unit Reviews). There is no penalty for getting a multiple-choice question incorrect and therefore you should answer every question. The directions on the AP Exam are as follows: Solve each of the following problems, using the available space for scratch work. After examining the form of the choices, decide which is the best of the choices given and place the letter of your choice in the corresponding box on the student answer sheet. Do not spend too much time on any one problem. In this exam: Unless otherwise specified, the domain of a function f is assumed to be the set of all real numbers x for which f (x) is a real number. The inverse of a trigonometric function f may be indicated using the inverse function notation f 1 or with the prefix “arc” (e.g., sin1 x arcsin x ). Section I - AP Calculus AB – McDermott 1. cos 3x dx (A) 3sin 3x C (E) 3sin 3x C 1 (B) sin 3 x C 3 1 sin 3 x C (C) 3 (D) sin 3x C 2. x e x dx (A) 2e x C 1 x e C (B) 2 (C) e x (D) 2 x e x C x (E) C e C 2 x 3. The slope field for a certain differential equation is shown to the right. Which of the following could be a solution to the differential equation with the initial condition y 0 1 ? (A) y cos x (D) y 1 x 2 1 (E) y 1 x2 y 1 x2 (C) y e x (B) 4. Which of the following is the solution to the differential equation dy x 2 with the initial condition dx y y(3) 2 ? A. y 2e 9x 3 /3 B. y 2e 9x C. y 2x 3 3 3 D. /3 E. 2x 3 14 3 2x 3 y 14 3 y Section I - AP Calculus AB – McDermott 5. sin( 2x) cos(2x)dx d. 2cos(2x) 2sin( 2x) C e. 2cos(2x) 2sin( 2x) C 1 1 cos(2x) sin( 2x) C 2 2 1 1 b. cos(2x) sin( 2x) C 2 2 c. 2cos(2x) 2sin( 2x) C a. 6. Shown to the right is a slope field for which of the following differential equations? dy xy a. dx dy xy y b. dx dy xy y c. dx dy xy x d. dx dy 3 x 1 e. dx 7. The acceleration of a particle moving along the x-axis at time t is given by a(t) = 6t 2. If the velocity is 25 when t = 3 and the position is 10 when t = 1, then the position x(t) = a. 9t 2 1 b. 3t 2 2t 4 c. t 3 t 2 4t 6 -1 8. òe -4 x d. t 3 t 2 9t 20 e. 36t 3 4t 2 77t 55 dx 0 a. -e-4 4 b. -4e-4 c. e-4 -1 d. 1 e-4 4 4 e. 4 - 4e-4 Section I - AP Calculus AB – McDermott 9. Using u = 2x +1, 2 ò 2x +1dx is equivalent to 0 1 1 2 a. ò u du 2 -1 b. 2 10. òx 2 ( ) ( ) x3 sin ( x 3 ) + C 3 11. If 2 ò 0 u du c. 1 2 5 ò 2 u du 1 d. ò 0 cos ( x 3 ) dx 1 a. - sin x 3 + C 3 1 b. sin x 3 + C 3 c. - 1 2 dy = cos ( 2x ) , then y = dx 1 a. - cos ( 2x ) + C 2 1 b. - cos 2 ( 2x ) + C 2 1 sin ( 2x ) + C c. 2 1 2 sin ( 2x ) + C d. 2 1 e. - sin ( 2x ) + C 2 x3 sin ( x 3 ) + C 3 x3 æ x4 ö e. sin ç ÷ + C 3 è4ø d. 5 u du e. ò 1 u du Section II - AP Calculus AB – McDermott Name_________________________________ AP CALCULUS AB Chapter 7 Review Section II: Free-Response Questions A CALCULATOR SHOULD ONLY BE USED ON PROBLEMS NUMBERED 3 OR LOWER Instructions For the free response portion of this exam, please write your answers in the space below the problem or in the space provided within the problem. Keep the following in mind while completing these problems. Show all of your work. Clearly label any functions, graphs, tables, or other objects that you use. Your work will be graded on correctness and completeness of your methods as well as your answers. Answers without supporting work may not receive credit. Justifications require that you give mathematical (noncalculator) reasons. Unless otherwise specified, answers (numerical or algebraic) need not be simplified. If you use decimal approximations in calculations, your work will be graded on accuracy. Unless otherwise specified, your final answers should be accurate to three places after the decimal point. Unless otherwise specified, the domain of a function f is assumed to be the set of all real numbers x for which f (x) is a real number. Section II - AP Calculus AB – McDermott 1. Consider the differential equation dy x , where y 0. dx y (a) The slope field for the given differential equation is shown below. Sketch the solution curve that passes through the point (3, –1), and sketch the solution curve that passes through the point (1, 2). (Note: The points (3, –1) and (1, 2) are indicated in the figure.) (b) Write an equation for the line tangent to the solution curve that passes through the point (1, 2). (c) Find the particular solution y f ( x) to the differential equation with the initial condition f (3) 1, and state its domain. Section II - AP Calculus AB – McDermott 2. The rate at which a baby bird gains weight is proportional to the difference between its adult weight and its current weight. At time t = 0, when the bird is first weighed, its weight is 20 grams. If B(t) is the weight of the bird, in grams, at time t days after it is first weighed, then dB 1 100 B . dt 5 Let y = B(t) be the solution to the differential equation above with initial condition B(0) = 20. (a) Is the bird gaining weight faster when it weighs 40 grams or when it weighs 70 grams? Explain your reasoning. d 2B d 2B (b) Find in terms of B. Use to explain why the graph of B cannot resemble the following dt 2 dt 2 graph. (c) Use separation of variables to find y = B(t), the particular solution to the differential equation with initial condition B(0) = 20. Section II - AP Calculus AB – McDermott 3. Consider the differential equation dy 3 x . dx y (a) Let y = f (x) be the particular solution to the given differential equation for 1 < x < 5 such that the line y = 2 is tangent to the graph of f. Find the x-coordinate of the point of tangency, and determine whether f has a local maximum, local minimum, or neither at this point. Justify your answer. (b) Let y = g(x) be the particular solution to the given differential equation for 2 < x < 8, with the initial condition g(6) = 4. Find y = g(x). Section III - AP Calculus AB – Dickman Answers Multiple Choice 1. C 2. A 3. E Free Response 4.