Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 1 Name_____________________________________ Cumulative Review—Part 1 Derivatives Review: Summary of Rules Each derivative rule is summarized for you below. Write an example that would best exemplify each rule. 1. Power rule f (x) = ax b then f '(x) = a× bx b -1 Example: 2. Constant rule f (x) = c then f '(x) = 0 Example: 3. Product rule y = f (x)× g(x) then y'= f (x)× g'(x) + g(x)× f '(x) Example: 4. Quotient rule y= f (x) g(x) × f '(x) - f (x) × g'(x) then y'= g(x) [g(x)]2 Only use it when the denominator is a function of x; not for something like y = Example: 5. Chain rule y = f (g(x)) then y'= f '(g(x))× g'(x) Or y = f (u) and u = g(x) then Example: dy dy du = × or y'= f '(u) × g'(x) dx du dx 2x - 5 3 Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 2 6. Logarithmic functions y = ln x then y'= 1 x more generally if y = ln u then dy 1 du = × dx u dx Example: 7. Exponential functions y = e x then y'= e x more generally if y = e u then dy du = eu × dx dx Example: 8. Trigonometric functions (You need to memorize the derivatives below.) d du d du sin u = cos u × cos u = - sin u × dx dx dx dx (You do NOT need to memorize the derivatives below.) d du tan u = sec 2 u × dx dx d du cot u = - csc 2 u × dx dx Examples: d du sec u = sec utan u × dx dx d du csc u = - csc ucot u dx dx Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 3 Important Techniques for Differentiation x 3 -1 1 3 -3 x2 - 3 x 1. Simplify first!!! y = rewrite as y = - x 2 y'= + x 2 4 4 4 8 4x 1 y ln rewrite as y ln1 ln x 2 0 2 lnx 2 lnx x 2 2. Implicit differentiation: when you cannot easily solve for y. Don’t forget to use the product rule when necessary: Example: x 2 + 2xy + 3y 2 = 7 dy dy 2x + 2x × + 2y + 6y × =0 dx dx dy dy 2x × + 6y × = -2x - 2y dx dx dy -2x - 2y - x - y = = dx 2x + 6y x + 3y 3. Logarithmic differentiation: take the natural log of both sides, use the laws of logs to simplify, and then use implicit differentiation to find the derivative. Example: y = 4 x × sin x 1 ln y = ln(4 x ) + ln( sin x ) = x ln 4 + ln(sin x) 2 1 dy 1 1 × = ln 4 + × × cos x y dx 2 sin x dy cos x ö æ = y × ln 4 + è dx 2sin x ø dy 1 æ ö = 4 x sin x × ln 4 + cot x è ø dx 2 Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 4 Derivative Review Questions – Complete on separate paper. Find the derivative of the following functions. You might find it helpful to simplify before taking the derivative. Simplify your answers. 2 2 1. g(t) = 2 2. h(x) = 3t (3x) 2 3. y = x 3 - 5 + 3 x3 5. f (x) = x 3 (5 - 3x 2 ) 7. f (x) = x 2 + x -1 x2 -1 9. f (x) = 3 x 2 -1 11. g(t) = t (1- t) 3 13. y = 4e x 15. y = 2 x e 2x 5 17. y = 1 + e 2x 19. y = ln x(x - 1) x-2 21. f (x) = ln 4x 23. y = ln ex 1 + ex 4. f (x) = x- 1 x 1ö æ 6. s = 4 - 2 (t 2 - 3t) è t ø 8. h(x) = 4x2 + x 3x 2 - 2 10. h(x) = 2 x +1 12. f (t) = (t +1) t 2 +1 14. y = x 2e x 16. y = 3 xe 3x ex 18. y = 1- xe x 20. y = x ln x 22. y = ln(x 2 - 2) 24. y = e -x sin x 1 x 25. y = cos3x 26. y = x 2 sin 27. y = cos2 x - sin 2 x 28. y = 29. y = sin x 30. y = sin5px cos x sin x 2 3 Intro to Calculus 31. y = cos x x2 33. y = 3sin2 4 x + x 36. Cumulative Review 32. y = Ms. LeBlanc, King Pg. 5 cos(x - 1) x -1 1 34. y = e sin 2x 2 35. f (x) = (x - 4) 3 x 2 (3x + 1) 2 If f and g are the functions whose graphs are shown, let u(x) = f (x)× g(x) and v(x) = f (x) . g(x) Find: y 4 a. u’(1) = ________ b. v’(5) = ________ f(x) 2 g(x) c. u’(0) = ________ 5 x -2 37. a. If g is a differentiable function, find an expression for the derivative of each of the following functions. æ 2x 4 + 3x ö 14g(x) y= b. c. y = lnç y = x 6 × g(x) ÷ e 7x è g(x) ø 38. Use implicit differentiation to find an equation of the (a.) tangent and (b.) normal line at the indicated point. at (-7, 3) 2y - y 3 = xy dy 39. Find dx of these equations. 2 a. 3x y - 2x = cos(y) 5 3 b. 3x - 2y = p y 3 2 c. e - 2x = xy Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 6 40. Using the graphs below, calculate the following derivatives. a. h'(1) if h(x) = f (x) × g(x) b. j'(1) if j(x) = c. m'(1) if m(x) = f (g(x)) d. k'(1) if k(x) = f ( f (x)) e. n'(4) if n(x) = g( f (x)) f (x) g(x) 41. Using the table below, calculate the following derivatives. a) If h(x) = f (g(x)), find h¢(1). b) If k(x) = g(x)× f (x), find k'(3). c) If j(x) = [ f (x)] , find j'(2). 3 d) If m(x) = f (x) , find m'(3). [ g(x)]2 x 1 2 3 f (x) g(x) f ¢(x) g¢(x) 3 1 7 2 8 2 4 5 7 6 7 9 Intro to Calculus Cumulative Review Answers to: Midterm Review—Part 1 -4 9 2. h'(x) = 3 3. y'= 3x 2 - 4 9x x -4 1. g'(t) = 3 3t 1 1 4. f '(x) = + 2 x 2 x3 5. f '(x) = 15x 2 (1- x 2 ) -x x2 +1 7. f '(x) = - 2 (x - 1) 2 -1 10. h'(x) = 3 (x + 1) 2 13. y'= 8xe x 16. y'= - 12 9 32 x 2 - 16x - 8. (3x - 2) 1 + 2t 11. g'(t) = (1- t) 4 2 2 e x ( x + 13 ) 17. y'= 2 23. y'1 ex 1 e x 1 2 ln x 1 1 e x 1 1 26. y'= - cos + 2x sin x x 25. y'= -3sin3x 28. y'= -csc 2 x or 29. y'= y'= -1 - cot 2 x cos x 2 sin x - x sin x - 2cos x x3 37 a. y'= x × g'(x) + 6g(x)x 1 38 a. y = - (x + 7) + 3 6 2 - 6xy 39. a. y' = 2 3x + sin y 5 8 40. a. -6 b. 41. a. 30 b. 77 2x 2 3(x 2 - 1) 3 2t 2 + t + 1 t2 +1 1- 2x e 2x e x (1 + e x ) 18. y'= (1- xe x ) 2 1 21. f '(x) = 2x 24. y'= e -x (cos x - sin x) 27. y'= -2sin2x or y'= -4 sin x cos x 30. y'= 5p × cos(5px) -(x -1)sin(x - 1) - cos(x - 1) (x - 1) 2 sin 2x 34. y'= cos2x × e 32. y'= 33. y'= 24sin(4x)cos(4x) +1 =12sin(8x) +1 (x - 4) 3 x 2 æ 3 2 6 ö 35. f '(x) = + 2 (3x + 1) è x - 4 x 3x + 1ø -2 36 a. 0 b. c. DNE 3 6 9. f '(x) = 3 t2 15. y'= -10e 2x (1 + e 2x ) 2 20. y'= ln x + 6. s'= 8t - 12 - 12. f '(t) = 14. y'= xe x (x + 2) 2 x 3 1 1 1 19. y'= + x x -1 x - 2 4x 22. y'= 3(x 2 - 2) 31. y'= Ms. LeBlanc, King Pg. 7 8x 3 + 3 g'(x) b. y'= 4 2x + 3x g(x) 5 b. y = 6(x + 7) + 3 5x 4 y' = b. 2y 2 c. 4 d. -1 c. 15 d. -14 e. -4 3 6x 2 + y 2 y' = c. e y - 2xy c. y'= 14 × g'(x) - 98g(x) e 7x Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 8 Midterm Review—Part 2 1. Refer to the graph of this function for the questions below. I. Where is it discontinuous? Name the type. II. Where is it not differentiable? Name the type. b. a. Where is this function discontinuous? For each point either name the type of discontinuity or explain why it is discontinuous. b. Where is this function not differentiable? For each point either name the type or explain why it is not differentiable. c. 2. For the functions below: I. Where is it discontinuous? Name the type. II. Where is it not differentiable? Name the type. a. d. Intro to Calculus Cumulative Review 3. Sketch the graph of the derivatives of these functions. b. a. Ms. LeBlanc, King Pg. 9 Intro to Calculus c. Cumulative Review Ms. LeBlanc, King Pg. 10 4. The graph below shows the position of a particle on a coordinate line. (a) When does the particle change direction? (b) When does the particle move at its greatest speed? (c) Graph the particle’s velocity. Think about the following questions: When is the particle’s velocity positive? negative? zero? 5. The graph below shows the velocity of a particle moving on a coordinate line. (a) When does the particle change direction? (b) When does the particle move at its greatest speed? (c) When does the particle have its greatest acceleration? (d) Graph the particle’s acceleration. Think about the following questions: When is the particle’s acceleration positive? negative? zero? Intro to Calculus Cumulative Review 6. The following graph shows the velocity of a skydiver after he jumps out of a plane. At some point during his fall, his parachute opens to slow his fall before he lands on the ground. Here, positive velocity indicates a downward speed. Ms. LeBlanc, King Pg. 11 10. The cost of extracting T tons of ore from a copper mine is C = f (T ), where C is in dollars. Suppose that f (1000) = 200,000 and f ¢(1000) = 250. a) What are the units of f ¢(T )? b) What is the average cost per ton of extracting 1,000 tons? c) What is the marginal cost per ton when 1,000 tons have been extracted? 11. Let f (t) be the number of centimeters of rainfall since midnight. t is the time since midnight, in hours. Approximate answers are okay. (a) When did the skydiver’s parachute open? (b) When did the skydiver land on the ground? (c) During freefall, an object reaches a terminal velocity where the object no longer gains speed due to air resistance. What is the skydiver’s terminal velocity during his freefall? 7. Find the value of A that makes this function continuous. 5x 10 x 6 y 2 6 x Ax 8. Find the value of A that makes this function continuous. ì Ax 2 + 3 x £2 y =í 2 î-x + 10x - 21 x > 2 9. Find the values of A and B that make this function both continuous and differentiable. ì Ax 3 + B x £ 4 y =í î 4 x + 12 x > 4 a) What are the units of f ¢( t) ? Explain the practical meaning of the following statements: b) f (7) =1.5. c) f ¢(7) = .15 d) f ¢(9) = 0 12. The following table gives the position of a moving body as a function of time. The position is measured in feet from some fixed point. The time is in seconds. t 0 0.5 1 1.5 2 2.5 3 3.5 4 (s) p 10 38 58 70 74 70 59 38 10 (ft) a) What is the body’s average velocity between t = 0 and t=4? b) What is the average velocity between t = 2.5 and t=3.5? c) Estimate the instantaneous velocity of the body at t=2.75? d) Approximately when does the body change direction? Intro to Calculus Cumulative Review Ms. LeBlanc, King Pg. 12 Answers to: Midterm Review—Part 2 1. a. x = -2: infinite, x = 1: jump, x = 4: jump, x = 6: removable b. x = -2: discontinuity, x = 0: cusp, x = 1: discontinuity, x = 3: corner, x = 4 and 6: discontinuity 2. a. i. nowhere, ii. x = 2, cusp c. i. x = 2, jump; ii. x = 2, discontinuity 3. a. b. 6. a. about t = 60 second b. about t = 104 seconds c. about 185 mph b. i. nowhere, ii. x = 4, corner d. i. nowhere, ii. x = -1, vertical tangent c. 4. a. about t = 3, 5 c. b. between t = 3 and 5 7. A = -5/9 8. A = -2 9. A = 1/12, B = 68/3 10. a. $ / ton of ore b. 200 $ / ton c. 250 $ / ton 11. a. cm/hr b. after 7 hours (at 7am) it has rained 1.5 cm c. at 7am it is raining at .15 cm / hour d. at 9 am it has stopped raining 12. a. 0 ft/sec c. -22 ft/sec b. -32 ft/sec d. about t = 2 sec 5. a. about t = 9.2 b. t = 7 c. greatest acceleration between t = 3 and 4, greatest acceleration is between t = 4 to 7 d.