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Calculus late transcendental 4th edition smith test bank

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Chapter 2
1. Find the equation of the tangent line to y  x 2 – 6 x at x  3.
A) y  –9 B) y  3 C) y  –9 x D) y  3 x
Ans: A Difficulty: Moderate Section: 2.1
2. Find an equation of the tangent line to y = f(x) at x = –3.
f  x   x3  x 2  x
A) y = –6x + 18 B) y = 22x – 45 C) y = 6x + 18
Ans: D Difficulty: Moderate Section: 2.1

D) y = 22x + 45

3. Find an equation of the tangent line to y = f(x) at x = 4.
f ( x)  2 x 3  5
A) y = 21x – 64 B) y = –96x – 251 C) y = 96x – 251
Ans: C Difficulty: Moderate Section: 2.1
4. Find the equation of the tangent line to y 
2
14
x
25
25
2
14
B)
y  – x
25
25
Ans: C Difficulty: Moderate

A)


D) y = 96x + 251

2
at x  2.
x3

y

C)
D)

2
14
x
25
25
2
14
y
x
25
25
y–

Section: 2.1

5. Find the equation of the tangent line to y  4 x + 4 at x  –3.
A) y  4 x + 10 B) y  2 x + 10 C) y  4 x + 20
Ans: B Difficulty: Moderate Section: 2.1


D) y  2 x + 20

6. Compute the slopes of the secant lines between the point at x = 1 and points close to it
(such as x = 0, x = 2, x = 0.9, x = 1.1) and use these results to estimate the slope of the
tangent line at x = 1. Round to two decimal places.
x 1
x 1
A) –1.30 B) –0.70 C) –0.20 D) 0.50
Ans: D Difficulty: Moderate Section: 2.1

Page 90


Chapter 2

7. Compute the slope of the secant line between the points x = 2.9 and x = 3. Round your
answer to the thousandths place.
f ( x)  sin(2 x)
A) –0.981 B) 1.852 C) –4.372 D) –1.963
Ans: B Difficulty: Easy Section: 2.1
8. List the points A, B, C, D, and E in order of increasing slope of the tangent line.

A) B, C, E, D, A B) A, E, D, C, B C) E, A, D, B, C
Ans: B Difficulty: Easy Section: 2.1

D) A, B, C, D, E

9. Use the position function s(t )  4.9t 2  8 meters to find the velocity at time t  1
seconds.
A) 3.1 m/sec B) –9.8 m/sec C) –1.8 m/sec D) –4.9 m/sec

Ans: B Difficulty: Moderate Section: 2.1
10. Use the position function s(t )  t – 1 meters to find the velocity at time t  5 seconds.
1
1
m/sec D)
m/sec
2
4
Difficulty: Moderate Section: 2.1

A) 2 m/sec B) 4 m/sec C)
Ans: D

11. Find the average velocity for an object between t = 2 sec and t = 2.1 sec if
f(t) = –16t2 + 100t + 10 represents its position in feet.
A) 34.4 ft/s B) 36 ft/s C) 32.8 ft/s D) 146 ft/s
Ans: A Difficulty: Moderate Section: 2.1

Page 91


Chapter 2

12. Find the average velocity for an object between t = –1 sec and t = –0.9 sec if
f(t) = 5sin(t) + 5 represents its position in feet. (Round to the nearest thousandth.)
A) 2.702 B) 3.108 C) 2.907 D) –2.907
Ans: C Difficulty: Moderate Section: 2.1
13. Estimate the slope of the tangent line to the curve at x = –2.

A) –1 B) –2 C) 2 D) 0

Ans: B Difficulty: Easy Section: 2.1
14. Estimate the slope of the tangent line to the curve at x = 2.

A) 2

1
1
D)
4
2
Difficulty: Easy Section: 2.1

B) –2

Ans: D

C)

Page 92


Chapter 2

15. The table shows the temperature in degrees Celsius at various distances, d in feet, from a
specified point. Estimate the slope of the tangent line at d  2 and interpret the result.
d
0
1
3
4

6
12
18
15
8
2
C
m  5; The temperature is increasing 5 C per foot at the point 2 feet from the
specified point.
m  –0.67; The temperature is decreasing 0.67 C per foot at the point 2 feet from
B)
the specified point.
m  –1.5; The temperature is decreasing 1.5 C per foot at the point 2 feet from the
C)
specified point.
m  18; The temperature is increasing 18 C per foot at the point 2 feet from the
D)
specified point.
Ans: C Difficulty: Moderate Section: 2.1

A)

16. The graph below gives distance in miles from a starting point as a function of time in
hours for a car on a trip. Find the fastest speed (magnitude of velocity) during the trip.
Describe how the speed during the first 2 hours compares to the speed during the last 2
hours. Describe what is happening between 2 and 3 hours.

Ans: The fastest speed occurred during the last 2 hours of the trip when the car traveled
at about 70 mph. The speed during the first 2 hours is 60 mph while the speed
from 8 to 10 hours is about 70 mph. Between 2 and 3 hours the car was stopped.

Difficulty: Moderate Section: 2.1
17. Compute f(2) for the function f ( x)  4 x3  5x .
A) 58 B) 43 C) 38 D) –43
Ans: B Difficulty: Moderate Section: 2.2

Page 93


Chapter 2

18. Compute f(5) for the function f ( x) 

4
.
x 4
2

2
40
40
40
B)
C) –
D) –
5
841
841
841
Ans: D Difficulty: Moderate Section: 2.2


A)

19. Compute the derivative function f(x) of f ( x) 
15
(3 x  7) 2
3
f ( x ) 
B)
(3 x  7) 2
Ans: A Difficulty: Moderate

A)

f ( x ) 

C)
D)

5
.
3x  7
5
(3 x  7) 2
15
f ( x ) 
(3 x  7) 2
f ( x ) 

Section: 2.2


20. Compute the derivative function f(x) of f ( x)  2 x 2  7 .
A)

f ( x) 

B)

f ( x) 

Ans: B

4 x

C)

2x  7
2x
2

2 x2  7
Difficulty: Moderate

D)
Section: 2.2

Page 94

f ( x) 

2 x


2 x2  7
2 x
f ( x ) 
4x  7


Chapter 2

21. Below is a graph of f ( x ) . Sketch a graph of f ( x) .

Ans:

Difficulty: Moderate

9+
Section: 2.2
Page 95


Chapter 2

22. Below is a graph of f ( x ) . Sketch a graph of f ( x) .

Ans:

Difficulty: Difficult

Section: 2.2


Page 96


Chapter 2

23. Below is a graph of f ( x) . Sketch a plausible graph of a continuous function f ( x ) .

Ans: Answers may vary. Below is one possible answer.

Difficulty: Moderate

Section: 2.2

Page 97


Chapter 2

24. Below is a graph of f ( x) . Sketch a plausible graph of a continuous function f ( x ) .

Ans: Answers may vary. Below is one possible answer.

Difficulty: Difficult

Section: 2.2

25. Compute the right-hand derivative D f (0)  lim
h 0

f (h)  f (0)

.
h 0
h
 –8 x – 9 if x  0
f ( x)  
10 x – 9 if x  0

f (h)  f (0)
and the left-hand
h

derivative D f (0)  lim

A)
C)
D f (0)  10 , D f (0)  –8
B)
D)
D f (0)  –8 , D f (0)  10
Ans: A Difficulty: Moderate Section: 2.2

Page 98

D f (0)  –9 , D f (0)  –9
D f (0)  1, D f (0)  1


Chapter 2

26. The table below gives the position s(t) for a car beginning at a point and returning 5 hours

later. Estimate the velocity v(t) at two points around the third hour.
t (hours)
s(t)
(miles)

0
0

1
15

2
50

3
80

4
70

5
0

Ans: The velocity is the change in distance traveled divided by the elapsed time. From
hour 3 to 4 the average velocity is (70 − 80)/(4 − 3) = −10 mph. Likewise, the
velocity between hour 2 and hour 3 is about 30 mph.
Difficulty: Easy Section: 2.2
27. Use the distances f(t) to estimate the velocity at t = 2.2. (Round to 2 decimal places.)
t 1.6
f(t) 43


1.8 2 2.2 2.4 2.6
38 32.5 28 23.5 18.5

2.8
13

A) 2250.00 B) 12.73 C) –22.50 D) –25.00
Ans: C Difficulty: Easy Section: 2.2
4 x 2 + 3 x if x  0
28. For f ( x)  
find all real numbers a and b such that f (0) exists.
 ax  b if x  0
a  8, b any real number
A)
a  11, b  0
B)
Ans: D Difficulty: Moderate

C)
D)
Section: 2.2

Page 99

a  3, b any real number
a  3, b  0


Chapter 2


29. Sketch the graph of a function with the following properties: f (0)  0, f (2)  1,
f (4)  –2, f (0)  1, f (2)  0, and f (4)  –3.
A)
5
4
3
2
1

y

x

-1-1
-2
-3
-4

1

2

3

4

5

B)

5
4
3
2
1

y

x

-1-1
-2
-3
-4

1

2

3

4

5

C)
5
4
3
2

1
-1-1
-2
-3
-4

y

x
1

2

3

4

5

6

Page 100


Chapter 2

D)
5
4
3

2
1
-1-1
-2
-3
-4

Ans: B

y

x
1

2

3

4

5

Difficulty: Moderate

Section: 2.2

30. Suppose a sprinter reaches the following distances in the given times. Estimate the
velocity of the sprinter at the 6 second mark. Round to the nearest integer.
t sec
f (t ) ft


5
121.7

5.5
142.5

6
158.5

6.5
174.7

7
193.9

A) 32 ft/sec B) 36 ft/sec C) 26 ft/sec D) 28 ft/sec
Ans: A Difficulty: Moderate Section: 2.2
31. Give the units for the derivative function.
c  t  represents the amount of a chemical present, in milligrams, at time t
seconds.
A) seconds per milligram
C)
B) seconds per milligram squared
D)
Ans: C Difficulty: Easy Section: 2.2

milligrams per second
milligrams per second squared


(2  h)3  (2  h)  10
32. lim
equals f (a ) for some function f ( x ) and some constant a.
h 0
h
Determine which of the following could be the function f ( x ) and the constant a.

A)
f ( x)  x3  x and a  2
B)
f ( x)  x3  x 2 and a  1
Ans: D Difficulty: Moderate

C)
D)
Section: 2.2

Page 101

f ( x)  x3  x  20 and a  1
f ( x)  x3  x and a  2


Chapter 2

1
1

2
(h  2) 4

33. lim
equals f (a ) for some function f ( x ) and some constant a. Determine
h 0
h
which of the following could be the function f ( x ) and the constant a.

1
and a  2
x2
2
B)
f ( x)  2 and a  2
x
Ans: A Difficulty: Moderate

A)

f ( x) 

C)
D)

1
and a  3
x2
1
f ( x)   2 and a  2
x
f ( x)  


Section: 2.2

34. Find the derivative of f(x) = –5x2 + 2x – 5.
A) –5x + 2 B) –10x2 – 5 C) –10x + 2 D) 10x – 2
Ans: C Difficulty: Easy Section: 2.3
35. Differentiate the function.
f (t )  8t 3  6 t
A)

f (t )  24t 2  12 t

C)

B)

f (t )  24t 2  12

D)

Ans: C

Difficulty: Moderate

36. Find the derivative of f ( x) 
1
+5
x2
1
B)
f ( x)  – 2 + 5

x
Ans: B Difficulty: Easy

A)

24t 5/ 2  3
t
2
24t  3
f (t ) 
t
f (t ) 

Section: 2.3

1
+ 5x + 2 .
x

f ( x) 

C)
D)
Section: 2.3

Page 102

1
+5
x

1
f ( x)  – 2 + 10 x 2
x
f ( x)  –


Chapter 2

37. Differentiate the function.
f (s)  3s3/ 2  5s 1/ 3
27 s 5 / 3  2
6s 2 / 3
27 s1/ 2  2 s1/ 3
f ( s ) 
B)
6
Ans: D Difficulty: Moderate

A)

f ( s ) 

C)
D)

27 s1/ 2  2 s 2 / 3
6
11/ 6
27 s  10
f ( s ) 

6s 4 / 3
f ( s ) 

Section: 2.3

–5 x 2 + 5 x – 2
38. Find the derivative of f ( x) 
.
7x

10 x – 5
7
10 x 5
B)
f ( x) 

7
7
Ans: C Difficulty: Moderate

A)

f ( x)  –

39. Find the derivative of f ( x) 

C)
D)
Section: 2.3


3x 2 + x + 1
.
x

9 x
1
1
C)
+

2
2 x 2 x3
12 x + 2
B)
D)
f ( x) 
x
Ans: A Difficulty: Moderate Section: 2.3
A)

f ( x) 

40. Differentiate the function.
f ( x)  x 6 x 2  6 x



A)

f ( x)  18x2  9 x


B)

f ( x) 

Ans: A

5
2
f ( x)  – + 2
7 7x
5x2 5x 2
f ( x)  –
+

7
7 7x

9 x
1
1

+
2
2 x 2 x3
1
1
f ( x)  9 x +
+
x

x3

f ( x) 



12 x3/ 2  3
x
Difficulty: Moderate

C)

f ( x)  12 x 2 – 3 x

D)

f ( x)  12 x – 3 x

Section: 2.3

Page 103


Chapter 2

41. Find the third derivative of f ( x)  2 x5 + 5 x –
12
x4

A)


f ( x)  120 x 2 –

B)

f ( x)  120 x 2 + 5 +

Ans: D

12
x4
Difficulty: Moderate

2
.
x

C)
D)

4
x3
12
f ( x)  120 x 2 + 4
x
f ( x)  40 x3 –

Section: 2.3

42. Find the second derivative of y  6 x +


7
.
x

d2y
21
d2y
21
d2y
21
B)
C)

6
+
–

2
2
2
dx
dx
dx
4 x5
4 x5
4 x5
Ans: B Difficulty: Moderate Section: 2.3
A)


D)

d2y
21

2
dx
4 x3

43. Using the position function s(t )  –5t 3 – 3t – 3 , find the acceleration function.
A) a (t )  –15t B) a (t )  –10t C) a (t )  –30t
Ans: C Difficulty: Moderate Section: 2.3

D) a(t )  –30t – 3

2
44. Using the position function s (t )  – t + , find the velocity function.
t

A)

v (t ) 

1

+

2
t2


2 t
1
2
v(t )  –
– 2
B)
2 t t
Ans: B Difficulty: Moderate

C)
D)

v (t ) 

1



2
t2

2 t
1
4
v(t )  –
– 2
2 t t

Section: 2.3


4
45. Using the position function s(t )  3t 4 + 4t 3 + , find the velocity function.
t

A)

v(t )  12t 3 + 12t 2 –

B)

v(t )  9t 3 + 8t 2 –

Ans: A

4
t2

4
t2
Difficulty: Moderate

4
t2

C)

v(t )  12t 3 + 12t 2 +

D)


v(t )  –12t 3 – 12t 2 –

Section: 2.3

Page 104

4
t2


Chapter 2

46. Using the position function s (t ) 

A) a(t )  –
Ans: D

9

B) a(t ) 

3

6
– 7 , find the acceleration function.
t

C) a (t )  –

2 t5

2 t5
Difficulty: Moderate Section: 2.3

3
t3

D) a(t ) 

9
2 t5

47. The height of an object at time t is given by h(t )  16t 2 – 2t + 6 . Determine the object's
velocity at t = 4.
A) 130 B) –136 C) –130 D) –66
Ans: C Difficulty: Easy Section: 2.3
48. The height of an object at time t is given by h(t )  2t 2 + t . Determine the object's
acceleration at t = 2.
A) 10 B) 4 C) 9 D) –4
Ans: B Difficulty: Easy Section: 2.3
49. Find an equation of the line tangent to f ( x)  x 2 + 3x – 9 at x = –6.
g ( x)  –9 x – 45
A)
g ( x)  –12 x – 45
B)
Ans: A Difficulty: Easy

C)
D)

g ( x)  –9 x – 3

g ( x)  –12 x – 3

Section: 2.3

50. Find an equation of the line tangent to f ( x)  7 x + 8x – 1at x = 3.

 –7 3 – 48 
7
C)
g ( x)  
3 +1
 x –
6
2


 7 3 + 16 
7
B)
D)
g ( x)  
3 +1
 x +
3
2


Ans: D Difficulty: Moderate Section: 2.3
A)


Page 105

 7 3 + 24 
7
g ( x)  
3
 x +
6
2


 7 3 + 48 
7
g ( x)  
3 –1
 x +
6
2




Chapter 2

51. Use the graph of f ( x ) below to sketch the graph of f ( x) on the same axes. (Hint:
sketch f ( x) first.)
9
8
7
6

5
4
3
2
1
-9 -8 -7 -6 -5 -4 -3 -2-1
-1
-2
-3
-4
-5
-6
-7
-8
-9

y

x
1 2 3 4 5 6 7 8 9

A)
9 y
8
7
6
5
4
3
x

2
1
-1 1 2 3 4 5 6 7 8 9
-9-8-7-6-5-4-3-2-1
-2
-3
-4
-5
-6
-7
-8
-9

B)
9 y
8
7
6
5
4
3
x
2
1
-1 1 2 3 4 5 6 7 8 9
-9-8-7-6-5-4-3-2-1
-2
-3
-4
-5

-6
-7
-8
-9

Page 106


Chapter 2

C)
9 y
8
7
6
5
4
3
x
2
1
-1 1 2 3 4 5 6 7 8 9
-9-8-7-6-5-4-3-2-1
-2
-3
-4
-5
-6
-7
-8

-9

D)
9 y
8
7
6
5
4
3
x
2
1
-1 1 2 3 4 5 6 7 8 9
-9-8-7-6-5-4-3-2-1
-2
-3
-4
-5
-6
-7
-8
-9

Ans: A

Difficulty: Difficult

Section: 2.3


52. Determine the real value(s) of x for which the line tangent to f ( x)  7 x 2 – 9 x – 4 is
horizontal.
9  193
9
9
C) x 
, x  0 B) x 
14
14
14
Ans: C Difficulty: Easy Section: 2.3

A) x 

D) x = 0

53. Determine the real value(s) of x for which the line tangent to f ( x)  2 x 4 – 16 x 2 – 8 is
horizontal.
A) x = –2, x = 2 B) x = 0, x = –2, x = 2 C) x = 0
Ans: B Difficulty: Easy Section: 2.3

D) x = 0, x = 2

54. Determine the value(s) of x, if there are any, for which the slope of the tangent line to
f ( x) | x 2 – 13x + 30 | does not exist.
A)
x  6.5
x  –10, x  –3
B)
Ans: C Difficulty: Moderate


C)
D)
Section: 2.3

Page 107

x  3, x  10
The slope exists for all values of x.


Chapter 2

55. Find the second-degree polynomial (of the form ax2 + bx + c) such that f(0) = 0, f '(0) = 5,
and f ''(0) = 1.
x2
x2
x2
x2
 5 x B)   5 x C)
 5 x  1 D)   5 x  1
2
2
2
2
Ans: A Difficulty: Moderate Section: 2.3

A)

56. Find a formula for the nth derivative f ( n ) ( x) of f ( x) 

20n !
C)
( x + 10) n 1
2n !
f ( n ) ( x)  ( 1) n 1
B)
D)
( x + 10) n
Ans: D Difficulty: Difficult Section: 2.3

A)

f ( n ) ( x)  (1) n 1

2
.
x + 10

20n !
( x + 10) n
2n !
f ( n ) ( x)  ( 1) n
( x + 10) n 1
f ( n ) ( x)  ( 1) n

57. Find a function with the given derivative.
f ( x)  36 x8
A) f ( x)  36 x9 B) f ( x)  4 x9 C) f ( x)  36 x7
Ans: B Difficulty: Moderate Section: 2.3


D) f ( x)  288 x7

58. Let f (t ) equal the average monthly salary of families in a certain city in year t. Several
values are given in the table below. Estimate and interpret f (2010) .
t
1995
2000
2005
2010
$1700
$2000
$2200
$2450
f (t )
f (2010)  2 ; The rate at which the average monthly salary is increasing each year
in 2010 is increasing by $2 per year.
f (2010)  2 ; The average monthly salary is increasing by $2 per year in 2010.
B)
f (2010)  50 ; The rate at which the average monthly salary is increasing each
C)
year in 2010 is increasing by $50 per year.
f (2010)  50 ; The average monthly salary is increasing by $50 per year in 2010.
D)
Ans: A Difficulty: Moderate Section: 2.3

A)

Page 108



Chapter 2

59. Find the derivative of f ( x) 





1

x – 5x  9 x2 –  .
x


45 3/ 2
1
x + 3/ 2
2
2x
45
1
B)
f ( x)  –135 x 2 + x3/ 2 + 3/ 2
2
2x
45
1
C)
f ( x)  135 x 2 + x3/ 2 – 3/ 2
2

2x
45
10
1
D)
f ( x)  –135 x 2 + x3/ 2 + + 3/ 2
2
x 2x
Ans: B Difficulty: Moderate Section: 2.4

A)

f ( x)  –135 x 2 –

60. Find the derivative of f ( x) 

6x + 2
.
9x – 5

48
2
2
B)
C) –
2
(9 x – 5)
3
3
Ans: D Difficulty: Moderate


A)

61. Find the derivative of f ( x) 

–48
(9 x – 5) 2
Section: 2.4

D)

9x
.
6 x2 – 4

–54 x 2 – 36
54 x 2 + 36
3
3
B)
C)
D)

2
2
2
2
2
2x 2
(6 x – 4)

(6 x – 4)
2x
Ans: A Difficulty: Moderate Section: 2.4
A)

Page 109


Chapter 2

62. Find the derivative of the function.
4x – 8 x
4x2 – 7

 4 – 4 x  4 x
1/ 2

A)

C)

D)





– 7   4 x – 8 x 8x

4x2 – 7


 4 – 4 x  4 x – 7    4 x – 8 x  8x
 4x – 7
 4 x – 8 x  8x   4 – 4 x  4 x – 7 
 4x – 7
 4 x – 8 x  8x   4 – 4 x  4 x – 7 
1/ 2

B)

2

2

2

2

Ans: B

2

1/ 2

2

1/ 2

2


2

4x2 – 7
Difficulty: Moderate



Section: 2.4



63. Find the derivative of f ( x)  –8 3 x + 5 x .
32 3
x +5
3
8
B)
f ( x)  – 3 x – 5
3
Ans: C Difficulty: Moderate

A)

f ( x) 

C)
D)

32 3
x +5

3
16
f ( x)  – 3 x + 10
3
f ( x)  –

Section: 2.4

64. Find the equation of the tangent line to the graph of y = f (x) at x = –2.
x+5
f  x  2
x +3
19
59
x+
49
49
19
22
B)
y  x+
7
7
Ans: A Difficulty: Moderate

A)

y

C)

D)

19
17
x–
49
49
19
16
y  – x+
7
7

y–

Section: 2.4

65. Find an equation of the line tangent to h( x)  f ( x) g ( x) at x  –2 if
f (–2)  3 , f (–2)  3 , g (–2)  –2 , and g (–2)  –1 .
A) y  3x – 12 B) y  3 x – 24 C) y  –9 x – 24
Ans: C Difficulty: Moderate Section: 2.4

Page 110

D) y  –9 x + 12


Chapter 2

f ( x)

at x  –3 if
g ( x)
f (–3)  –2 , f (–3)  1 , g (–3)  1 , and g (–3)  2 .

66. Find an equation of the line tangent to h( x) 

A) y  –3 x + 13 B) y  5 x + 13 C) y  –3 x – 11
Ans: B Difficulty: Moderate Section: 2.4

D) y  5 x – 17

67. A small company sold 1000 widgets this year at a price of $10 each. If the price
increases at rate of $1.25 per year and the quantity sold increases at a rate of 250 widgets
per year, at what rate will revenue increase?
A) $312.5/year B) $3750/year C) $1250/year
Ans: B Difficulty: Moderate Section: 2.4

D) $4062.5/year

( x 2 + 2) 4
68. Find the derivative of f ( x) 
.
6

2
x( x 2 + 2)3
3
1
B)
f ( x)  x( x 2 + 2)3

3
Ans: C Difficulty: Moderate

A)

f ( x) 

C)
D)

4
x( x 2 + 2)3
3
1
f ( x)  x( x 2 + 2)3
6

f ( x) 

Section: 2.5

69. Find the derivative of f ( x)  x 2 – 2 .
A)

f ( x) 

B)

f ( x) 


Ans: D

2x
x –2
4x
2

x2 – 2
Difficulty: Moderate

C)

f ( x) 

D)

f ( x) 

–x
x2 – 2
x
x2 – 2

Section: 2.5

70. Differentiate the function.
f (t )  t 3 t 7 – 2

A)


f (t ) 

B)

f (t ) 

Ans: C

7t 3 – 12t 2
2 t7 – 2
3t 2

2 t7 – 2
Difficulty: Difficult

C)

f (t ) 

D)

f (t ) 

Section: 2.5

Page 111

13t 9 – 12t 2
2 t7 – 2
21t 8

2 t7 – 2


Chapter 2

x
.
x +1

71. Find the derivative of f ( x) 

2

A)


1
1


2  x x2  1


B)

 x 
 

 x2  1 
2 x x2  1






Ans: B

 



3
x2  1 

x



3

1



f ( x) 

B)

f ( x) 


3

(5 x + 9)
Difficulty: Moderate

f ( x) 

B)

C)

D)



f ( x)  

f ( x)  

f ( x)  

f ( x)  

Ans: A

x3 + 5  4 x











f ( x) 

D)

f ( x) 

2

x3 + 5  4 x



3

16 x3 + 5  3x 2
2 x3 + 5



x3 + 5  4 x



2


2 x3 + 5  8
x3 + 5  4 x



3

2 x3 + 5  8
x3 + 5  4 x



2

Difficulty: Difficult

x2  1

C)

Section: 2.5

8 x3 + 5  3x 2
x3 + 5

1








2 x2



x2  1

2

.

(5 x 2 + 9)3
40 x

73. Differentiate the function.

A)

5x2 + 9

–20 x

2






Section: 2.5
4

72. Find the derivative of f ( x) 

Ans: A

D)

Difficulty: Moderate

A)

C)


1
1
 x x2  1

2  x x2  1


Section: 2.5

Page 112

20 x
(5 x 2 + 9)3

8x
(5 x 2 + 9)3










Chapter 2

1

74. Find an equation of the line tangent to f ( x) 

x2 – 3

at x = 2.

A) y = –2x + 3 B) y = –2x C) y = 2x + 3 D) y = –2x + 5
Ans: D Difficulty: Moderate Section: 2.5
75. Use the position function s(t )  t 2  65 meters to find the velocity at t = 4 seconds.
4
1
2
m/s C)
m/s D)

m/s
9
9
9
Difficulty: Moderate Section: 2.5

A) 9 m/s

B)

Ans: B

76. Compute the derivative of h( x)  f  g ( x)  at x = –8 where
f (–8)  8 , g (–8)  2 , f (–8)  4 , f (2)  –7 , g (–8)  9 , and g (2)  7 .
A) h(–8)  36 B) h(–8)  72 C) h(–8)  –63
Ans: C Difficulty: Moderate Section: 2.5

D) h(–8)  16

77. Find the derivative where f is an unspecified differentiable function.
f (9 x 4 )
A) 36 x3 f (9 x 4 ) B) (36 x3  9 x 4 ) f (9 x 4 ) C) f (36 x3 )
Ans: A Difficulty: Moderate Section: 2.5

D) f (36 x3  9 x 4 )

78. Find the derivative where f is an unspecified differentiable function.
4

A)


f  x
1

4 3  f  x 

Ans: D

4

B)

f  x
4 3  f  x 

Difficulty: Moderate

4

C)

1
4 4  f  x 

3

D)

f  x
4 4  f  x 


3

Section: 2.5

79. Find the second derivative of the function.
f ( x)  100  x 2

A)

f ( x) 

B)

f ( x) 

Ans: C

100 x
(100  x 2 )3/ 2

x 2  100
(100  x 2 )3/ 2
Difficulty: Moderate

C)

f ( x)  

100

(100  x 2 )3/ 2

D)

f ( x)  

100 x
(100  x 2 )3/ 2

Section: 2.5

Page 113


Chapter 2

80. Find a function g ( x) such that g ( x)  f ( x).
f ( x)   x 2 + 5  (2 x)
4

5

A)

 x3
 x2
+
5
x



 3
 5

B)

g ( x)   x + 5  (16 x)
2

Ans: D

3

Difficulty: Moderate

C)

g ( x)   x 2 + 5 

D)

x
g ( x) 

2

5

+ 5


5

5

Section: 2.5

81. Use the table of values to estimate the derivative of h( x)  f  g ( x)  at x = 6.
x
f(x)
g(x)

–1
–5
4

0
–4
2

1
–3
0

2
–4
0

3
–5
2


4
–6
4

5
–5
2

6
–3
0

7
–1
–1

A) h(6)  2 B) h(6)  –3 C) h(6)  –2 D) h(6)  3
Ans: A Difficulty: Moderate Section: 2.5
82. Find the derivative of f ( x)  5sin( x) – 3cos(3 x)  x .
f ( x)  5cos x + 9sin 3 x  1
A)
C)
f ( x)  5cos x + 3sin 3x  1
B)
D)
Ans: A Difficulty: Easy Section: 2.6

f ( x)  –5cos x – 9sin 3 x  1
f ( x)  cos x – 3sin 3 x  1


83. Find the derivative of f ( x)  7sin 2 x + 9 x 2 .
f ( x)  –14sin x cos x + 18 x
A)
C)
f ( x)  14sin x cos x + 9 x
B)
D)
Ans: D Difficulty: Easy Section: 2.6

84. Find the derivative of f ( x) 

–9 cos x 2
.
x2

–18( x 2 sin x 2  cos x 2 )
C)
x3
18( x sin x 2  cos x 2 )
f ( x) 
B)
D)
x3
Ans: C Difficulty: Moderate Section: 2.6

A)

f ( x)  14sin x + 18 x
f ( x)  14sin x cos x + 18 x


f ( x) 

Page 114

18( x 2 sin x 2  cos x 2 )
x3
18( x 2 sin x 2  cos x 2 )
f ( x) 
x4
f ( x) 


×