Past Board Exam Problems in Differential Calculus Engineering Mathematics (University of Nueva Caceres) Studocu is not sponsored or endorsed by any college or university Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) Past Board Exam Problems in Differential Calculus 1. 2. 3. CE Board Exam November 1993 Find the second derivative of y by implicit differentiation from the equation 4x2 + 8y2 = 36. A. 64x2 C. 9. 4 1- 4x 2 B. C. - x 4x 1 x 2(x + 1)2 x 3(x + 1 - x - 2x 13 x (x + 1)3 x3 (x + 1)3 x2 9 3 y answer 4 32xy 16 3 y 9 - CE Board Exam May 1998 Find the slope of the curve x2 + y2 – 6x + 10y + 5 = 0 at point (1, 0). A. 1/5 B. 2/5 C. 1/4 D. 2 10. CE Board Exam May 1996 Find the slope 2of the tangent to the curve y = 2x – x + x3 at (0, 2). A. 1 B. 2 C. 3 D. 4 x )2 D. ) x +1 x (x + 1)2 (x + 1)3 2 6. 8. answer CE Board Exam November 1995 The derivative with respect to x of 2cos2 (x2 + 2) A. 2sin (x2 + 2) cos (x2 + 2) B. -2sin (x2 + 2) cos (x2 + 2) C. 8xsin (x2 + 2) cos (x2 + 2) D. -8xsin (x2 + 2) cos (x2 + 2) CE November 1997 What is the first derivative of y = arcsin 3x? 11. CE Board Exam May 1996 Find the slope of the ellipse x2 + 4y2 – 10x – 16y + 5 = 0 at the point where y = 2 + 80.5 and x = 7. A. -0.1463 B. -0.1538 C. -0.1654 D. -0.1768 12. CE Board Exam May 1995 Find the equation of the line normal to x2 + y2 = 25 at the point (4, 3). A. 5x + 3y = 0 B. 3x – 4y = 0 C. 3x + 4y = 0 5x – 3y = 0 13. CE November 1998 Determine the slope of the curve x2 + y2 – 6x – 4y – 21 = 0 at (0, 7). A. 3/5 B. -2/5 C. -3/5 D. answer CE May 1999 Find the second derivative of y = x-2 at x = 2. A. 96 B. 0.375 C. -0.25 D. -0.875 B. CE Board Exam November 1996 3 A. 3 7. D. Find the derivative of 1 9x 3 2 1 9x 2 2 ( D. 3 1 9x 2 3 1 9x 2 D. CE Board Exam May 1997 Find the derivative of arcos 4x. -4 A. answer 1- 16x 2 4 B. 1- 16x -4 1- 4x 2 B. C. CE Board Exam November 1994 What is the derivative with respect to x of (x + 1)3 – x3? A. 3x + 6 B. 3x – 3 C. 6x – 3 D. 6x + 3 D. 5. CE Board Exam November 1997 x2 - 1 Evaluate Lim 2 x 1 x 3x - 4 A. 1/5 B. 2/5 C. 3/5 D. 4/5 C. 4. A. 2/5 14. CE May 1998 Find the slope of the line whose parametric equations are x = 4t + 6 and y = t – 1. A. -4 B. 1/4 C. 4 D. -1/4 15. CE November 1999 Find the slope of the curve y = 64(4 + x)1/2 at (0, 12). A. 0.67 B. 1.5 C. 1.33 D. 0.75 16. CE May 1999 Find the angle that the line 2y – 9x – 18 = 0 makes with the x-axis. A. 74.77° B. 4.5° C. 47.77° D. 77.47° 17. CE November 1998 What is the radius of curvature at point (1, 2) of the curve 4x – y2 = 0? A. 6.21 B. 5.21 C. 5.66 D. 6.66 18. CE November 1997 Find the radius of curvature of the curve y2 - 4x = 0 at point (4, 4). A. 24.4 B. 25.4 C. 23.4 D. 22.4 19. CE November 1999 Find the radius of curvature of the curve x = y3 at (1, 1). A. 4.72 B. 3.28 C. 4.67 D. 5.27 20. CE November The chords of the ellipse 64x2 + 25y2 = 1600 having equal slopes of 1/5 are bisected by its diameter. Determine Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) the equation of the diameter of the ellipse? A. 5x – 64y = 0 B. 64x – 5y = 0 C. 5x + 64y = 0 D. 64x + 5y = 0 21. CE Board Exam May 1995 A wall “h” meters high is 2 m away from the building. The shortest ladder that can reach the building with one end resting on the ground outside the wall is 6 m. How high is the wall in meters? A. 2.34 B. 2.24 C. 2.44 D. 2.14 22. CE Board Exam May 1997 Find the minimum amount of tin sheet that can be made into a closed cylinder having a volume of 108 cu. inches in square inches. A. 125.50 B. 127.50 C. 129.50 D. 123.50 23. CE Board Exam November 1996 A Norman window is in the shape of a rectangle surmounted by a semicircle. What is the ratio of the width of the rectangle to the total height so that it will yield a window admitting the most light for a given perimeter? A. 1 B. 1/2 C. 2 D. 2/3 24. CE Board Exam May 1998 Determine the diameter of a closed cylindrical tank having a volume of 11.3 cu. m to obtain the minimum surface area. A. 1.22 B. 1.64 C. 2.44 D. 2.68 25. CE Board Exam November 1998 Water is pouring into a conical vessel 15 cm deep and having a radius of 3.75 cm across the top if the rate at which the water rises is 2 cm/sec, how fast is the water flowing into the conical vessel when the water is 4 cm deep? A. 2.37 m3/sec B. 5.73 m3/sec C. 6.28 m3/sec D. 4.57 m3/sec 26. CE Board Exam May 1997 Car A moves due east at 30 kph at the same instant car B is moving S 30° E, with a speed of 60 kph. If the distance from A to B is 30 km, find how fast is the distance between them separating after one hour. A. 36 kph B. 38 kph C. 40 kph D. 45 kph 27. CE Board Exam November 1996 A car starting at 12:00 noon travels west at a speed of 30 kph. Another car starting from rest starting from the same point at 2:00 pm travels north at 45 kph. Find how fast (in kph) the two are separating at 4:00 pm? A. 49 B. 51 C. 53 D. 55 28. CE Board Exam May 1996 Two railroad tracks are perpendicular to each other. At 12:00 pm there is a train at each track approaching the crossing at 50 kph, one being 100 km and the other 150 km away from the crossing. How fast in kph is the distance between the two trains changing at 4:00 pm? A. 67.08 B. 68.08 C. 69.08 D. 70.08 29. CE Board Exam May 1998 Water is running into a hemispherical bowl having a radius of 10 cm at a constant rate of 3 cm3/min. When the water is x cm deep, the water level is rising at the rate of 0.0149 cm/min. What is the value of x? A. 3 B. 2 C. 4 D. 5 30. CE May 1999 The number of newspaper copies distributed is given by C = 50t2 – 200t + 10000, where t is in years. Find the minimum number of copies distributed from 1995 to 2002 A. 9850 B. 9800 C. 10200 D. 7500 31. CE May 1999 A rectangular box having a square base and open at the top is to have a capacity of 16823 cc. Find the height of the box to use the least amount of material. A. 16.14 cm B. 32.28 cm C. 18.41 cm D. 28.74 cm 32. CE May 1998, November 1999 The volume of a closed cylindrical tank is 11.3 cubic meters. If the total surface is a minimum, what is its base radius, in m? A. 1.44 B. 1.88 C. 1.22 D. 1.66 33. CE May 1998 An object moves along a straight line such that, after t minutes, its distance from its starting point is D = 20t + 5/(t + 1) meters. At what speed, in m/minute will it be moving at the end of 4 minutes? A. 39.8 B. 49.8 C. 29.8 D. 19.8 34. CE May 1996 The speed of the traffic flowing past a certain downtown exit between the hours of 1:00 pm and 6:00 pm is approximately V = t3 – 10.5t2 + 30t + 20 miles per hour, where t = number of hours past noon. What is the fastest speed of the traffic between 1:00 pm and 6:00 pm in mph? A. 50 B. 46 C. 32.5 D. 52 35. CE May 1997 A car drives east from point A at 30 kph. Another car B starting from B at the same time drives S 30° W toward A at 60 kph. B is 30 km away from A. How fast in kph is the distance between the two cars changing after one hour? A. 76.94 kph B. 78.94 kph C. 75.94 kph D. 77.94 kph 36. CE November 1998 There is a constant inflow of a liquid into a conical vessel 15 ft deep and Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) 7.5 feet in diameter at the top. Water is rising at the rate of 2 feet per minute when the water is 4 feet deep. What is the rate of inflow in cu. Ft per minute? A. 8.14 B. 7.46 C. 9.33 D. 6.28 37. CE May 2003 What is the radius of curvature of the curve y2 = 16x = 0 at the point (4, 8)? A. -0.044 B. -0.088 C. -0.066 D. -0.033 38. CE November 2002 Suppose that x years after founding in 1975, a certain employee association has a membership of f(x) = 100(2x3 – 45x2 + 264x), at what time between 1975 and 1989 was the membership smallest? A. 1983 B. 1985 C. 1984 D. 1986 39. CE November 2002 A 3 meter long steel pipe has its upper end leaning against a vertical wall and lower end on a level ground. The lower end moves away at a constant rate of 2 cm/s. How fast is the upper end moving down, in cm/s, when the lower end is 2 m from the wall? A. 1.81 B. 1.66 C. 1.79 D. 1.98 40. CE May 2002 A particle moves according to the parametric equations: y = 2t2 and x = t3 where x and y are displacement (in meters) in x and y direction, respectively and t is time in seconds. Determine the acceleration of the body after t = 3 seconds. A. 12.85 m/s2 B. 18.44 m/s2 C. 21.47 m/s2 D. 5.21 m/s2 41. CE May 2002 Determine the shortest distance from point (4, 2) to the parabola y2 = 8x. A. 2.83 B. 3.54 C. D. Differentiate y = sec (x2 + 2) A. 2x cos (x2 + 2) B. -cos (x2 + 2) cot (x2 + 2) C. 2x sec (x2 + 2) tan (x2 + 2) D. cos (x2 + 2) 2.41 6.32 42. CE November 2001 Water flows into a tank having the form of a frustum of a right circular cone. The tank is 4 m tall with upper radius of 1.5 m and the lower radius of 1 m. When the water in the tank is 1.2 m deep, the surface rises at the rate of 0.012 m/s. Calculate the discharge of water flowing into the tank in m3/s. A. 0.02 B. 0.05 C. 0.08 D. 0.12 49. EE Board Exam October 1997 Differentiate y = log(x2+1)2 A. 4x(x2 + 1) 4x log10 e B. answer (x 2 1) C. log e(x)(x2 + 1) D. 2x(x2 + 1) 50. EE Board Exam October 1997 Differentiate (x2 + 2)1/2 A. 43. CE November 2003 The motion of a particle is defined by the parametric equation x = t3 and y = 2t3. Determine the velocity when t = 2. A. 14.42 B. 16.25 C. 12.74 D. 18.63 B. C. D. B. C. D. C. D. 3x4 2x2 7 5x 3 x 3 Undefined 3/5 infinity 0 47. EE Board Exam October 1997 Differentiate y = ex cos x2 A. -ex sin x2 B. ex (cos x2 – 2x sin x2) C. ex cos x2 – 2x sin x2 D. -2xex sin x 48. EE Board Exam October 1997 2x2 + 2x 3 2(x + 2) x5/2 + x1/2 1 2 53. EE Board Exam October 1997 If y = 4cos x + sin 2x, what is the slope of the curve when x = 2? A. -2.21 B. -4.94 C. -3.25 D. -2.21 46. EE Board Exam October 1994 A. B. C. D. (x2 + 2)3/2 52. EE Board Exam April 1995 Find y’ if y = arcsin (cos x). A. -1 B. -2 45. EE Board Exam April 1993 1 cos x Evaluate Lim x0 x2 A. 0 B. 1/2 C. 2 D. -1/2 x (x 2 2)1/ 2 answer 2x (x 2 2)1/ 2 51. EE Board Exam October 1997 If y = (t2 + 2)2 and t = x1/2, determine dy/dx. A. 3/2 44. CE November 2003 The sum of two numbers is K. The product of one by the cube of the other is to be a minimum. Determine one the numbers. A. 3K/4 B. 3K/8 C. 3K/2 D. 3K/7 Evaluate Lim (x 2 1)1/ 2 2 x 54. EE Board Exam April 1997 Locate the points of inflection of the curve y = f(x) = x2ex. A. 2 3 B. 2 C. 2 2 answer D. 2 55. EE Board Exam April 1990 Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) The sum of two positive numbers is 50. What are the numbers if their product is to be the largest possible. A. 24 and 26 B. 28 and 22 C. 25 and 25 D. 20 and 30 56. EE Board Exam March 1998 A triangle has variable sides x, y, z subject to the constraint such that the perimeter P is fixed to 18 cm. What is the maximum possible area for the triangle? A. 15.59 cm2 B. 18.71 cm2 C. 17.15 cm2 D. 14.03 cm2 57. EE Board Exam October 1997 A farmer has enough money to build only 100 meters of fence. What are the dimensions of the field he can enclose this maximum area? A. 25 m by 25 m B. 15 m by 35 m C. 20 m by 30 m D. 22.5 m by 27.5 m 58. EE Board Exam April 1997 The cost of fuel in running a locomotive is proportional to the square of the speed and is $25 per hour for a speed of 25 miles per hour. Other costs amount to $ 100 per hour, regardless of the speed. What is the speed which will make the cost per mile a minimum? A. 40 B. 55 C. 50 D. 45 59. EE Board Exam April 1997 A poster is to contain 300 m2 of printed matter with margins of 10 cm at the top and bottom and 5 cm at each side. Find the over-all dimensions, if the total area of the poster is a minimum. A. 27.76 cm, 47.8 cm B. 20.45 cm, 35.6 cm C. 22.24 cm, 44.5 cm D. 25.55 cm, 46.7 cm 60. EE Board Exam March 1998 A fencing is limited to 20 ft in length. What is the maximum rectangular area that can be fenced in using two perpendicular corner sides of an existing wall? A. 120 B. 100 C. D. 140 190 61. EE Board Exam October 1992 The cost per hour of running a motor boat is proportional to the cube of the speed. At what speed will the boat run against a current of 8 kph in order to go a distance most economically? A. 10 kph B. 13 kph C. 11 kph D. 12 kph 62. EE Board Exam October 1993 A boatman is at A which is 4.5 km from the nearest point B on a straight shore BM. He wishes to reach in minimum time a point C situated on the shore 9 km from B. How far from C should he land if he can row at the rate of 6 kph and can walk at the rate of 7.5 kph? A. 4.15 km B. 3.0 km C. 3.25 km D. 4.0 km A. B. C. D. 0.64 0.56 0.75 0.45 m/min m/min m/min m/min 66. EE Board Exam October 1993 A standard cell has an emf “E” of 1.2 volts. If the resistance “R” of the circuit is increasing at a rate of 0.03 ohm/sec, at what rate is the current “I” changing at the instant when the resistance is 6 ohms? Assume Ohm’s law E = IR. A. -0.002 amp/sec B. 0.004 amp/sec C. -0.001 amp/sec D. 0.003 amp/sec 67. ECE Board Exam November 1991 ( ) 2 Evaluate the limit Lim x + 3x - 4 x →4 A. B. C. D. 24 26 28 30 68. ECE Board Exam November 1994 πx 63. EE Board Exam October 1993 At any distance x from the source of light, the intensity of illumination varies directly as the intensity of the source and inversely as the square of x. Suppose that there is a light at A and another at B having an intensity 8 times that of A. The distance AB is 4 m. At what point from A on the line AB will the intensity of illumination be least? A. 2.15 m B. 1.33 m C. 1.50 m D. 1.92 m 64. EE Board Exam April 1997 The coordinates (x, y) in feet of a moving particle P is given by x = cos t – 1 and y = 2sin t + 1, where t is the time in seconds. At what extreme rates in fps is P moving along the curve? A. 3 and 2 B. 3 and 1 C. 2 and 0.5 D. 2 and 1 65. EE Board Exam October 1993 Water is flowing into a conical cistern at the rate of 8 m3/min. If the height of the inverted cone is 12 m and the radius of its circular opening is 6 m. How fast is the water level rising when the water is 4 m deep? Evaluate Lim(2 - x)tan 2 x →1 A. B. C. D. e2π e2/π 0 ∞ 69. ECE Board Exam April 1998 x- 4 Evaluate lim x® 4 x2 A. B. C. D. - x - 12 undefined 0 infinity 1/7 70. ECE Board Exam April 1993 2 Evaluate lim x - 4 x® 2 x - 2 A. 0 B. 2 C. 4 D. 6 71. ECE November 1997 Evaluate the limit (ln x)/x as x approaches positive infinity. A. 1 B. 0 C. e D. infinity 72. ECE Board Exam November 1991 Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) Differentiate the equation y = x 2 + 2x A. B. C. D. (x + 1)2 x2 x +1 answer x x +1 2x 2x 2 x +1 73. ECE November1997 Given the equation y = (elnx)2, find y’ A. lnx B. 2( ln x) /x C. 2x D. 2eln x 74. ECE March 1996 The derivative of ln (cos x) is A. sec x B. -sec x C. -tan x D. tan x vertex, the slope of the tangent line is zero. A. (2, -3) B. (3, -2) can be inscribed in the cone to the volume of the cone? A. 44% B. 46% C. D. C. D. (-1, -3) (-2, 3) 80. ECE Board Exam April 1999 Find the equation of the line normal to x2 + y2 = 5 at the point (2, 1). A. y = 2x B. x = 2y C. 2x+ 3y = 3 D. x + y = 1 81. ECE Board Exam November 1991 In the curve y = 2 + 12x – x3, find the critical points. A. (2, 18) and (-2, -14) B. (-2, 18) and (2, -14) C. (2, 18) and (2, -14) D. (-2, 18) and (-2, 14) 82. ECE Board Exam November 1996 Find the radius of curvature of a parabola y2 – 4x = 0 at point (4, 4). A. 22.36 units B. 25.78 units C. 20.33 units D. 15.42 units 75. ECE November 1997 If y = x(ln x), find d2y/dx2. A. 1/x2 B. -1/x C. 1/x D. -1/x2 76. ECE Board Exam November 1991 Find the slope of the line tangent to the curve y = x3 – 2x + 1 at x = 1. A. 1 B. ½ asss C. 1/3 D. 1/4 77. ECE Board Exam November 1991 Give the slope of the curve at the point (1, 1): y = x3/4 – 2x + 1. A. 1/4 B. -1/4 C. 1 1/4 D. -1 1/4 78. ECE November 1998 Find the slope of x2y = 8 at the point (2, 2). A. 2 B. -1 C. -1/2 D. -2 79. ECE Board Exam April 1999 Find the coordinates of the vertex of the parabola y = x2 – 4x + 1 by making use of the fact that at the 83. ECE Board Exam November 1996 Find the radius of curvature at any point in the curve y + ln cos x = 0. A. cos x B. 1.5707 C. sec x D. 1 84. ECE Board Exam April 1999 Find the minimum distance from the point (4, 2) to the parabola y2 = 8x. A. 4 B. 2 answer C. D. 2 85. ECE April 1998 Find the point in the parabola y2 = 4x at which the rate of change of the ordinate and abscissa are equal. A. (1, 2) B. (2, 1) C. (4, 4) D. (-1, 4) 56% 65% 87. ECE Board Exam April 1998 A statue 3 m high is standing on a base of 4 m high. If an observer’s eye is 1.5 m above the ground, how far should he stand from the base in order that the angle subtended by the statue is a maximum? A. 3.41 m B. 3.51 m C. 3.71 m D. 4.41 m 88. ECE Board Exam November 1991 A balloon is released from the ground 100 meters from an observer. The balloon rises directly upward at the rate of 4 meters per second. How fast is the distance between them changing after 1 second? A. 1.68 m/sec B. 1.36 m/sec C. 1.55 m/sec D. 1.49 m/sec 89. ECE Board Exam April 1998 A balloon is rising vertically over a point A on the ground at the rate of 15 ft/sec. A point B on the ground is level with and 30 ft from A. When the balloon is 40 ft from A, at what rate is its distance from B changing? A. 13 fps B. 15 fps C. 12 fps D. 10 fps 90. ECE Board Exam November 1998 What is the allowable error in measuring the edge of the cube that is intended to hold 8 cu. m, if the error of the computed volume is not to exceed 0.03 cu. m? A. 0.002 B. 0.003 C. 0.0025 D. 0.001 91. ECE Board Exam November 1997, November 1999 86. ECE Board Exam November 1996 Given a cone of diameter x and altitude of h. What percent is the volume of the largest cylinder which Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) If y = x ln x, find A. B. C. D. -1/x -1/x2 1/x2 1/x d2y dx2 92. ECE Board Exam April 1999 The depth of water in a cylindrical tank 4 m in diameter is increasing at the rate of 0.7 m/min. Find the rate at which the water is flowing into the tank. A. 2.5 m3/min B. 1.5 m3/min C. 6.4 m3/min D. 8.8 m3/min 93. ECE Board Exam November 1999 Two posts, one 8 m high and the other 12 m high are 15 m apart. If the posts are supported by a cable running from the top if the first post to a stake on the ground and then back to the top of the second post, find the distance to the lower post to the stake to use minimum amount of wire. A. 6 m B. 8 m C. 9 m D. 4 m 94. ECE Board Exam April 2000 Find the approximate increase by the use of differentials, in the volume of the sphere if the radius increases from 2 to 2.05 in one second. A. 2.12 B. 2.51 C. 2.86 D. 2.25 95. ECE Board Exam April 2000, April 1999 What is the area of the largest rectangle that can be inscribed in a semi-circle of radius 10? 2 50 A. B. C. 100 1000 D. 50 96. ECE Board Exam April 2000 If ln(ln y) + ln y = ln x, find y’. A. x/(x + y) B. x/(x – y) C. y/(x + y) D. y/(x - y) 97. ECE Board Exam April 2000 The volume of the sphere is increasing at the rate of 6 cm3/hr. At what rate is its surface area increasing (in cm2/hr) when the radius is 50 cm? A. 0.50 B. 0.30 C. D. = 18t + 9t2. What is the velocity at t = 3? A. 36 B. 18 C. 72 D. 54 0.40 0.24 98. ECE Board Exam April 2000, November 2001 Water is running out a conical funnel at the rate of 1 cu. in per second. If the radius of the base of the funnel is 4 in and the altitude is 8 in., find the rate at which the water level is dropping when it is 2 in. from the top. A. -3/2 pi in/s B. 2/3 pi in/s C. -4/9 pi in/s D. -1/9 pi in/s 99. ECE Board Exam November 2000 If y = 2x + sin 2x, find x if y’= 0. A. π/2 B. π/4 C. 2π/3 D. 3π/2 100. ECE Board Exam November 2000 The equation of the line tangent to the curve y = x + 5/x at point P(1, 3) is A. 4x – y + 7 = 0 B. x + 4y – 7 = 0 C. 4x + y – 7 = 0 D. x – 4y + 7 = 0 101. ECE Board Exam November 2000 If y = arctan (ln x), find dy/dx at x = 1/e. A. e B. e/2 C. e/3 D. e^2 105. ECE Board Exam November 2001 Find the height of a right circular cylinder of maximum volume, which can be inscribed in a sphere of radius 10 cm. A. 14.12 cm B. 15.11 cm C. 12.81 cm D. 11.55 cm 106. ECE Board Exam November 2001 What is the second derivative of a function y = 5x3 + 2x + 1? A. 25x B. 30x C. 18 D. 30 107. ECE Board Exam April 1999, April 2002 Find the minimum distance from the point (4,2) to the parabola y2 = 8x. A. 4 B. D. answer 3 2 108. ECE Board Exam November 2002, November 2004 A statue 3.2 m high stands on a pedestal such that its foot is 0.4 m above an observer’s eye level. How far from the statue must the observer stand in order that the angle subtended by the statue will be a maximum? A. 1.1 m B. 1.5 m C. 1.2 m D. 1.4 m 102. ECE Board Exam November 2000 Find the change in y = 2x – 3 if x changes from 3.3 to 3.5. A. 0.4 B. 0.2 C. 0.5 D. 0.3 103. ECE Board Exam April 2001 The radius of a sphere is r inches at time t seconds. Find the radius when the rates of increase of the surface area and the radius are numerically equal. A. 1/8π in. B. 1/4π in. C. 2π in. D. π2 in. 2 C. 109. ECE Board Exam November 2002 104. ECE Board Exam November 2001 The distance of a body travels as a function of time and is defined by x(t) Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) A person in a rowboat is 3 km from a point P on a straight shore while his destination is 5 km directly east of point P. If he is able to row 4 km per hour and walk 5 km per hour, how far from the destination must he land on the shore in order to reach his destination in the shortest possible time? A. 1 km B. 2.5 km C. 3 km D. 2 km 110. ECE Board Exam November 2002 What is the slope of the curve y = 1 + x2 at the point where y = 10? A. 8 B. 3 C. 9 D. 6 111. ECE Board Exam November 2002 Given the equation: 2y3 = 3x2 – 5. Determine the slope of the line tangent at (4, 1). A. 4 B. 3 C. 1/4 D. 1 112. ECE Board Exam April 2002 What is the maximum area of a rectangle that can be inscribed in a right triangle with base of 8 cm and a height of 6 cm? A. 12 sq cm B. 48 sq cm C. 24 sq cm D. 50 sq cm 113. ECE Board Exam April 2003 2 B. 3 2 C. 8 2 answer D. 5 2 Determine the slope of the tangents to the parabola y = -x2 + 5x – 6 at the points of intersection with the x-axis. A. 2 B. -4 C. 1 D. -2 115. ECE Board Exam April 2003 A drop of ink is placed on a piece of paper and causes a circular blot that increases in area at the rate of 1 sq mm/sec. At what rate does the radius of the bolt increase when its area is 1 sq mm? 1/ π2/2 / 2π answer C. D. π/ 116. ECE Board Exam April 2003 -1 2pi 0 -2 123. ECE Board Exam November 2004 A conical vessel 1 cm deep and with a radius of 6 cm at the top, is being filled with water. If the rate at which the water rises is 2 cm/sec, how fast is the volume increasing when the water is 4 cm deep? A. 3 pi B. 4 pi C. 8 pi D. 16 pi 117. ECE Board Exam November 2003 Determine the equation of the line tangent to the parabola y = x2 at the point (1, 1). A. y = 2x + 1 B. y = 2 – x C. y = 2x – 1 D. y = 2 + x 118. ECE Board Exam November 2003 A fisherman on a wharf 1.2 meters above the level of still water is pulling a rope tied to a boat at the rate of 2 meters per minute. How fast is the boat approaching the wharf when there are two meters of rope out? A. 2.5 m/min B. 1.25 m/min C. 2.0 m/min D. 3.0 m/min 124. ECE Board Exam November 2004 A customer is using a straw to drink iced tea from a right circular glass at the rate of 6 cubic cm per minute. If the height of the glass is 12 cm and the diameter is 6 cm, how fast is the level of the iced tea decreasing at a constant rate in cm per min? A. 0.212 B. 1.570 C. 0.318 D. 0.747 What is the second derivative of y with respect to w in the following equation: y = (3w2 – 4)(3w2 + 4)? A. 36w3 B. 9w4 C. 9w16 D. 108w2 125. ECE Board Exam November 2003 A condominium is to be constructed in a rectangular lot with a perimeter of 800 m. What is the largest area that can be enclosed by fencing the perimeter? A. 5 hectares B. 4 hectares C. 6 hectares D. 3.5 hectares 120. ECE Board Exam November 2003 114. ECE Board Exam April 2003 A. B. A. B. C. D. 119. ECE Board Exam November 2003 Solve for the radius of a right circular cone of maximum volume which can be inscribed in a sphere of radius 12 cm. A. Solve for dy/dx if x = 2 + t and y = 1 + t2. A. 2x B. t C. 0 D. 2t A stone is thrown into still water and causes concentric circular ripples. The radius of the ripples increases at the rate of 12 inches/sec. At what rate does the area of the ripples increases (in sq inch per sec) when its radius is 3 inches? A. 402.55 B. 275.60 C. 226.19 D. 390.50 126. ECE Board Exam April 2005 The cost of a product is a function of the quantity q of the product: c(q) = q2 – 2000q + 100. What should be the quantity for which the cost is a minimum? A. 2500 B. 1000 C. 2000 D. 1500 121. ECE Board Exam November 2004 In how many equal parts can a wire, 50 cm long be cut so that the product of its parts is a maximum? A. 15 B. 19 C. 13 D. 20 127. ECE November 1996 122. ECE Board Exam November 2003 æsin x3 ÷ ö ç ÷ Evaluate lim 2 x® 0ççèsin x ÷ ø Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) A rectangular field is to be fenced into four equal parts. What is the size of the largest field that can be fenced this way with a fencing length of 1500 feet if the division is to be paralleled to one side? A. 65,200 B. 62,500 C. 64,500 D. 63,500 128. ECE November 1997 Three sides of a trapezoid are each 8 cm long. How long is the 4th side, when the area of the trapezoid has the greatest value? A. 16 cm B. 15 cm C. 12 cm D. 10 cm 129. ECE March 1996, November 1996 The altitude of a cylinder of maximum volume that can be inscribed in a right circular cone of radius r and height h is A. h/3 B. 2h/3 C. 3h/2 D. h/4 130. ECE November 1995 The height of a right circular cylinder is 50 inches and decreases at the rate of 4 inches per second, while the radius of the base is 20 inches and increases at the rate of one inch per second. At what rate is the volume changing? A. 11310 cu. m/sec B. 1275 cu. m/sec C. 11130 cu. m/sec D. 1257 cu. m/sec 131. ECE November 1995, March 1996 A point on the curve where the second derivative of a function is equal to zero is called A. maxima B. minima C. point of inflection D. point of intersection 132. ECE November 1995 The point on the curve where the first derivate of a function is zero and the second derivative is positive is called A. maxima B. minima C. point of inflection D. point of intersection A. B. C. D. At the minimum point, the slope of the tangent line is A. negative B. infinity C. positive D. zero 134. ECE November 1996 B. C. 135. ECE April 1998 Point of the derivatives, which do not exist (and so equals zero) are called A. stationary points B. maximum points C. maximum and minimum points D. minimum point D. If the second derivative of the equation of a curve is equal to the negative of the equation of the same curve, the curve is: A. a cissoid B. a paraboloid C. a sinusoid D. an exponential A. B. C. D. Lim x-4 A. B. C. D. following Find the derivative of the function 2x2 + 8x + 9 with respect to x. A. DF(x) = 4x - 8 B. DF(x) = 2x + 9 C. DF(x) = 2x + 8 D. DF(x) = 4x + 8 limit: 144. ME April 1998 Differentiate ax2 + b to the 1/2 power. A. -2ax B. 2ax C. 2ax+ b D. ax + 2b 1 0 2 infinite 139. ME Board Exam April 1997 What is the first derivative of the expression (xy)x = e? A. 0 x B. y (1+ ln xy) answer C. - y x -y 145. ME April 1997 If y A. B. C. D. Given the function f(x) = x3 – 5x + 2, find the value of the first derivative at x = 2, f’(2). A. 7 B. 3x2 - 5 C. 2 D. 8 (1- ln xy) x Find the derivative with respect to x the function - 2x2 = cos x, what is dy/dx? sec x -sec x sin x -sin x 146. ME October 1997 140. ME Board Exam April 1998 A. 3x If a is a simple constant, what is the derivative of y = xa? A. axa-1 B. (a – 1)x C. xa-1 D. ax 138. ME Board Exam October 1997 the 2 - 3x2 143. ME April 1996 0 1 8 16 Compute x+ 4 lim x® ¥ x - 4 - 3x2 142. ME April 1996 x 2 - 16 x 4 answer Find the derivative of (x + 5)/(x2 – 1) with respect to x. A. DF(x) = (-x2 – 10x – 1)/(x2 - 1)2 B. DF(x) = (-x2 + 10x – 1)/(x2 - 1)2 C. DF(x) = (x2 – 10x – 1)/(x2 - 1)2 D. DF(x) = (-x2 – 10x + 1)/(x2 + 1)2 137. ME Board Exam April 1998 Evaluate -3x 141. ME April 1996 136. ECE November 1997 D. 133. ECE November 1996 f”(a) = is not equal to zero f”(a) = 0 f”(a) > 0 f”(a) < 0 147. ME Board Exam April 1998 2 - 3x2 At the inflection point of y = f(x) where x = a, Downloaded by Carl Vincent P. Taboada (lract090@gmail.com) Find the partial derivative with respect to x of the function xy2 – 5y + 6. A. y2 – 5 B. y2 C. D. given below? P is profit and x is unit of production. P = 200,000 – x – [1.1/(x + 1)]8 A. 285,000 B. 200,000 C. 250,000 D. 305,000 xy – 5y 2xy 148. ME Board Exam October 1997 Find the second derivative of x3 – 5x2 +x=0 A. 10x - 5 B. 6x - 10 C. 3x + 10 D. 3x2 – 5x 155. ME Board Exam October 1996 Water is pouring into swimming pool. After t hours, there are t + t1/2 gallons in the pool. At what rate is the water pouring into the pool when t = 9 hours? A. 7/6 gph B. 8/7 gph C. 6/5 gph D. 5/4 gph 149. ME Board Exam April 1998 Given the function f(x) = x to the 3rd power -6x + 2. Find the first derivative at x = 2. A. 6 B. 7 C. 3x2 - 5 D. 8 156. ME October 1997 A function is given below, what x value maximizes y? y2 + y + x2 – 2x = 5 A. 2.23 B. -1 C. 5 D. 1 150. ME April 1996 Find the slope of the line tangent to the curve y = x3 – 2x + 1 at x = 1. A. 1 B. 1/2 C. 1/3 D. 1/4 157. ME April 1998 151. ME April 1996 If y = x to the 3rd power – 3x. Find the maximum value of y. A. 0 B. -1 C. 1 D. 2 Find the slope of the tangent to a parabola y = x2 at a point on a curve where x = 1/2. A. 0 B. 1 C. 1/4 D. -1/2 158. ME April 1998 As x increases uniformly at a rate of 0.002 feet per second, at what rate is the expression (1 + x) to the 3rd power increasing when x becomes 8 feet? A. 430 cfs B. 0.300 cfs C. 0.486 cfs D. 0.346 cfs 152. ME Board Exam April 1998 A box is to be constructed from a piece of zinc 20 sq. in. by cutting equal squares from each corner and turning up the zinc to form the side. What is the volume of the largest box that can be so constructed? A. 599.95 cu. inches B. 592.58 cu. inches C. 579.50 cu. inches D. 622.49 cu. inches 159. ME April 1998 The distance a body travels is a function of time and is given by x(t) = 16t + 8t2. Find its velocity at t = 3. A. 64 B. 56 C. 54 D. 44 153. ME Board Exam April 1996 The cost C of a product is a function of the quantity x of the product: C(x) = x2 – 4000x + 50. Find the quantity for which the cost is a minimum. A. 1000 B. 1500 C. 2000 D. 3000 154. ME Board Exam October 1996 What is the maximum profit when the profit versus production function is as 160. A. B. C. D. Downloaded by Carl Vincent P. Taboada (lract090@gmail.com)