Problem 4.4.8a
Sketch a graph of a function f with the following properties.
f' < 0 and f" < 0, for x < -1
Problem 4.4.8d
Sketch a graph of a function f with the following properties.
f' < 0 and f" < 0, for 8 < x < 10
Problem 4.4.11
Sketch a continuous function f on some interval that has the properties described. Answers will vary.
The function f satisfies f'(-2) = 2, f'(0) = 0, f'(1) = -3 and f'(4) = 1.
Problem 4.4.13g
Let ƒ(x) = (x - 3) (x + 3)²
g. Use your work in parts (a) through (f) to sketch a graph of ƒ.
Problem 4.4.14d
if ƒ(x) = 1 / (3x⁴ + 5) , it can be shown that ƒ'(x) = 12x³ / (3x⁴ + 5)² and ƒ"(x) = 180x² (x² + 1) (x + 1) (x - 1) / (3x⁴ + 5)³ . Use these functions to complete the following steps.
d. Identify the local extreme values and inflection points of ƒ .
Problem 4.4.14g
if ƒ(x) = 1 / (3x⁴ + 5) , it can be shown that ƒ'(x) = 12x³ / (3x⁴ + 5)² and ƒ"(x) = 180x² (x² + 1) (x + 1) (x - 1) / (3x⁴ + 5)³ . Use these functions to complete the following steps.
g. Use your work in parts (a) through (f) to sketch a graph of ƒ .
Problem 4.4.17
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = x³ - 6x² + 9x
Problem 4.4.20
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = x⁴ + 4x³
Problem 4.4.36
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = ln (x² + 1)
Problem 4.4.23
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = x³ - 6x² - 135x
Problem 4.4.44
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = 1/(e⁻ˣ - 1)
Problem 4.4.46
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = e⁻ˣ²/₂
Problem 4.4.49
49–54. {Use of Tech} Graphing with technology Make a complete graph of the following functions. A graphing utility is useful in locating intercepts, local extreme values, and inflection points.
ƒ(x) = 1/3 x³ - 2x² - 5x + 2
Problem 4.4.26
Graphing functions Use the guidelines of this section to make a complete graph of f.
f(x) = x³ - 147x + 286
Problem 4.4.73
{Use of Tech} Special curves The following classical curves have been studied by generations of mathematicians. Use analytical methods (including implicit differentiation) and a graphing utility to graph the curves. Include as much detail as possible.
x²/₃ + y²/₃ = 1 (Astroid or hypocycloid with four cusps)
Problem 4.4.74
{Use of Tech} Special curves The following classical curves have been studied by generations of mathematicians. Use analytical methods (including implicit differentiation) and a graphing utility to graph the curves. Include as much detail as possible.
y = 8/(x² + 4) (Witch of Agnesi)
Problem 4.4.755
{Use of Tech} Special curves The following classical curves have been studied by generations of mathematicians. Use analytical methods (including implicit differentiation) and a graphing utility to graph the curves. Include as much detail as possible.
x³ + y³ = 3xy (Folium of Descartes)
Problem 4.4.77
{Use of Tech} Special curves The following classical curves have been studied by generations of mathematicians. Use analytical methods (including implicit differentiation) and a graphing utility to graph the curves. Include as much detail as possible.
x⁴ - x² + y² = 0 (Figure-8 curve)
Problem 4.4.78a
{Use of Tech} Elliptic curves The equation y² = x³ - ax + 3, where a is a parameter, defines a well-known family of elliptic curves.
a. Plot a graph of the curve when a = 3.
Problem 4.4.57
Functions from derivatives Use the derivative f' to determine the x-coordinates of the local maxima and minima of f, and the intervals on which f is increasing or decreasing. Sketch a possible graph of f (f is not unique).
f'(x) = 10 sin 2x on [-2π, 2π]
Problem 4.4.66
{Use of Tech} A pursuit curve A man stands 1 mi east of a crossroads. At noon, a dog starts walking north from the crossroads at 1 mi/hr (see figure). At the same instant, the man starts walking and at all times walks directly toward the dog at s > 1 mi/hr . The path in the xy-plane followed by the man as he pursues the dog is given by the function y = ƒ(x) = s/2 ((x(ˢ⁺¹)/ˢ) /(s+1) - (x(ˢ⁺¹)/ˢ / s-1)) + s/ s² - 1
Select various values of s > 1 and graph this pursuit curve. Comment on the changes in the curve as s increases. <IMAGE>
Problem 4.4.78c
{Use of Tech} Elliptic curves The equation y² = x³ - ax + 3, where a is a parameter, defines a well-known family of elliptic curves.
c. By experimentation, determine the approximate value of a (3 < a < 4)at which the graph separates into two curves.
Problem 4.5.17
Rectangles beneath a semicircle A rectangle is constructed with its base on the diameter of a semicircle with radius 5 and its two other vertices on the semicircle. What are the dimensions of the rectangle with maximum area?
Problem 4.5.18
Rectangles beneath a parabola A rectangle is constructed with its base on the x-axis and two of its vertices on the parabola y = 48 - x². What are the dimensions of the rectangle with the maximum area? What is the area?
Problem 4.5.23
Closest point on a curve What point on the parabola y = 1 - x² is closest to the point (1, 1)?
Problem 4.5.25
Minimum distance Find the point P on the line y = 3x that is closest to the point (50, 0). What is the least distance between P and (50, 0)?
Problem 4.5.5a
Suppose the objective function P= xy is subject to the constraint 10x + y = 100, where x and y are real numbers.
a. Eliminate the variable y from the objective function so that P is expressed as a function of one variable x.
Problem 4.5.6b
Suppose S = x + 2y is an objective function subject to the constraint xy = 50, for x > 0 and y > 0.
b. Find the absolute minimum value of S subject to the given constraint.
Problem 4.5.30
Shortest ladder A 10-ft-tall fence runs parallel to the wall of a house at a distance of 4 ft. Find the length of the shortest ladder that extends from the ground to the house without touching the fence. Assume the vertical wall of the house and the horizontal ground have infinite extent.
Problem 4.5.33
Maximum-volume cone A cone is constructed by cutting a sector from a circular sheet of metal with radius 20. The cut sheet is then folded up and welded (see figure). Find the radius and height of the cone with maximum volume that can be formed in this way. <IMAGE>
Ch. 4 - Applications of the Derivative
