AP Calculus AB - Fulton County Schools

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AP Calculus AB
Review of Curve Sketching Problems
Multiple Choice
= class problem
= homework problem
1969 #7
For what value of k will y = x 
a) -4
b) -2
k
have a relative maximum at x = -2?
x
c) 2
d) 4
e) none of these
1969 #17
The graph of y  5x 4  x 5 has a point of inflection at
a) (0, 0) only
b) (3, 162) only
c) (4, 256) only
d) (0, 0) and (3, 162)
e) (0, 0) and (4, 256)
1969 #21
At x = 0, which of the following is true of the function f defined by f ( x )  x 2  e 2 x ?
a) f is increasing
b) f is decreasing
c) f is discontinuous
d) f has a relative minimum
e) f has a relative maximum
1969 #30
If a function f is continuous for all x and if f has a relative maximum at (-1, 4) and a relative
minimum at (3, -2), which of the following statements must be true?
a)
b)
c)
d)
e)
The graph of f has a point of inflection somewhere between x = -1 and x = 3.
f '(-1) = 0
The graph of f has a horizontal asymptote
The graph of f has a horizontal tangent at x = 3
The graph of f intersects both axes
1973 #22
Given the function defined by f ( x )  3x 5  20x 3 , find all values of x for which the graph of f is
concave up.
a) x > 0
d) x  2
b)  2  x  0 or x  2
e) -2 < x < 2
c) -2 < x < 0 or x > 2
1985 #16
The function defined by f ( x )  x 3  3x 2 for all real numbers x has a relative maximum at x =
a) -2
b) 0
c) 1
d) 2
e) 4
1988 #4
The graph of y 
a) x < 0
5
is concave downward for all values of x such that
x2
b) x < 2
c) x < 5
d) x > 0
e) x > 2
1993 #15 (calculator question)
For what value of x does the function f ( x )  ( x  2)( x  3) 2 have a relative maximum?
a) -3
b)  73
c)  25
d)
7
3
e)
5
2
1993 #21 (calculator question)
At what value of x does the graph of y 
a) 0
b) 1
c) 2
1
1
 3 have a point of inflection?
2
x
x
d) 3
e) at no value of x
1997 #5
The graph of y  3x 4  16x 3  24 x 2  48 is concave down for
a) x < 0
b) x > 0
c) x < -2 or x >  23
d) x <
2
3
or x > 2
e)
2
3
 x2
1997 #85 (calculator question)
If the derivative of f is given by f '( x )  e x  3x 2 , at which of the following values of x does f
have a relative maximum value?
a) -0.46
b) 0.20
c) 0.91
d) 0.95
e) 3.73
1998 #1
What is the x-coordinate of the point of inflection on the graph of y  13 x 3  5x 2  24
a) 5
b) 0
c)  103
d) -5
e) -10
1998 #19
If f ''( x )  x ( x  1)( x  2) 2 , then the graph of f has inflection points when x =
a) -1 only
b) 2 only
c) -1 and 0 only
d) -1 and 2 only
e) -1, 0, and 2 only
1998 #79 (calculator question)
y = g '(x)
y = f '(x)
a
b
a
b
y = h '(x)
a
b
The graphs of the derivatives of functions f, g, and h are shown above. Which of the functions f,
g, or h have a relative maximum on the open interval a < x < b?
a) f only
b) g only
c) h only
d) f and g only
e) f, g, and h
1998 #89 (calculator question)
If g is a differentiable function such that g(x) < 0 for all real numbers x and if
𝑓 ′ (𝑥) = (𝑥 2 − 4)𝑔(𝑥), which of the following is true?
a)
b)
c)
d)
e)
f has a relative maximum at x = -2 and a relative minimum at x = 2
f has a relative minimum at x = -2 and a relative maximum at x = 2
f has relative minima at x = -2 and x = 2
f has relative maxima at x = -2 and x = 2
it cannot be determined if f has any relative extrema
FREE RESPONSE
1985 #6
y = f '(x)
-3
-2
-1
1
2
3
Note: This is the graph of the derivative of f, not the graph of f.
The figure above shows the graph of f ', the derivative of a function f. The domain of the
function f is the set of all x such that –3  x  3.
(a) For what values of x, -3 < x < 3, does f have a relative maximum? A relative minimum?
Justify your answer.
(b) For what values of x is the graph of f concave up? Justify your answer.
(c) Find all points of inflection on the graph of f.
(d) Use the information found in parts (a) and (b) and the fact that f (-3) = 0 to sketch a possible
graph of f.
-3
-2
-1
1
2
3
1992 #1
Let f be the function defined by f (x) = 3x5 – 5x3 + 2.
(a) On what intervals is f increasing?
(b) On what intervals is the graph of f concave upward?
(c) Write the equation of each horizontal tangent line to the graph of f.
1991 #5
Let f be a function that is even and continuous on the closed interval [-3, 3]. The function f and
its derivatives have the properties indicated in the table below.
x
0
0<x<1
1
1<x<2
2
2<x<3
f (x)
1
Positive
0
Negative
-1
Negative
f '(x) Undefined
Negative
0
Negative
Undefined
Positive
f ''(x) Undefined
Positive
0
Negative
Undefined
Negative
(a) Find the x-coordinate of each point at which f attains an absolute maximum value or an
absolute minimum value. For each x-coordinate you give, state whether f attains an absolute
maximum or an absolute minimum.
(b) Find the x-coordinate of each point of inflection on the graph of f. Justify your answer.
(c) In the xy-plane provided below, sketch the graph of a function with all the given
characteristics of f.
1
-3
1
-1
-2
2
3
-1
1993 #5
(calculator
question)
(1, 1)
1
Note: this is the graph of the
derivative of f, not the graph of f
1
2
The figure above shows the graph of f ', the derivative of f. The domain of f is the set of all x
such that 0 < x < 2.
a) Write an expression for f '(x) in terms of x.
b) Given that f (1) = 0, write an expression for f (x) in terms of x.
c) In the xy-plane provided below, sketch the graph of y = f (x).
2
1
-2
1
-1
-1
-2
2
1996 #1
Note: this is the graph of the
derivative of f, not the graph of f
-3
1
-1
-2
2
4
3
5
The figure above shows the graph of f ', the derivative of a function f. The domain of f is the set
of all real numbers x such that –3 < x < 5.
(a) For what values of x does f have a relative maximum? Why?
(b) For what values of x does f have a relative minimum? Why?
(c) On what intervals is the graph of f concave upward? Use f ' to justify your answer.
(d) Suppose that f (1) = 0. In the xy-plane provided, draw a sketch that shows the general shape
of the graph of the function f on the open interval 0 < x < 2.
1
2
2000 #3
-7
-6
-5
-4
-3
-2
-1
1
2
3
4
5
6
7
The figure above shows the graph of f ', the derivative of the function f, for -7 ≤ x ≤ 7. The graph
of f ' has horizontal tangent lines at x = -3, x = 2, and x = 5, and a vertical tangent line at x = 3.
a)
b)
c)
d)
Find all values of x, -7 < x < 7, at which f attains a relative minimum. Justify your answer.
Find all values of x, -7 < x < 7, at which f attains a relative maximum. Justify your answer.
Find all values of x, -7 < x < 7, at which f ''(x) < 0.
At what value of x, -7 ≤ x ≤ 7, does f attain its absolute maximum? Justify your answer.
2002 #4
(0, 3)
(-2, -3)
(2, -3)
The graph of the function f shown above consists of two line segments. Let g be the function
𝑥
given by 𝑔(𝑥) = ∫0 𝑓(𝑡)𝑑𝑡.
a) Find g (-1), g '(-1) and g ''(-1)
b) For what values of x in the open interval (-2, 2) is g increasing? Explain your reasoning.
c) For what values of x in the open interval (-2, 2) is the graph of g concave down? Explain
your reasoning.
d) On the axes below, sketch the graph of g on the closed interval [-2, 2].
2
2003 #4
(-3, 1)
-3
1
-2
1
-1
2
3
4
-1
-2
(4, -2)
Let f be a function defined on the closed interval -3 ≤ x ≤ 4 with f (0) = 3. The graph of f ', the
derivative of f, consists of one line segment and a semicircle, as shown above.
a) On what intervals, if any, is f increasing? Justify your answer.
b) Find the x-coordinate of each point of inflection on the graph of f on the open interval
-3 < x < 4. Justify your answer.
c) Find an equation for the line tangent to the graph of f at the point (0, 3).
d) Find f (-3) and f (4). Show the work that leads to your answers.
2004 #5
(-3, 2)
The graph of the function f shown to the
right consists of a semicircle and three line
segments. Let g be the function given by
𝑥
𝑔(𝑥) = ∫−3 𝑓(𝑡)𝑑𝑡.
(0, 1)
(2, 1)
(4, -1)
(-5, -2)
a) Find g(0) and g '(0).
b) Find all values of x in the open interval (-5, 4) at which g attains a relative maximum. Justify
your answer.
c) Find the absolute minimum value of g on the closed interval [-5, 4]. Justify your answer.
d) Find all values of x in the open interval (-5, 4) at which the graph of g has a point of
inflection.
2005 #4
Let f be a function that is continuous on the interval [0, 4). The function f is twice differentiable
except at x = 2. The function f and its derivatives have the properties indicated in the table
below, where DNE indicates that the derivatives of f do not exist at x = 2.
x
0
0<x<1
1
1<x<2
2
2<x<3
3
3<x<4
f
-1
negative
0
positive
2
positive
0
negative
f'
4
positive
0
positive
DNE
negative
-3
negative
f ''
-2
negative
0
positive
DNE
negative
0
positive
a) For 0 < x < 4, find all values of x at which f has a relative extremum. Determine whether
f has a relative maximum or a relative minimum at each of these values. Justify your
answer.
b) On the axes provided, sketch the graph of a function that has all the characteristics of f.
𝑥
c) Let g be the function defined by 𝑔(𝑥) = ∫1 𝑓(𝑡)𝑑𝑡 on the interval (0, 4). For 0 < x < 4,
find all values of x at which g has a relative extremum. Determine whether g has a
relative maximum or a relative minimum at each of these values. Justify your answer.
d) For the function g defined in part (c), find all values of x, for 0 < x < 4, at which the graph
of g has a point of inflection. Justify your answer.
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