04.06.2022 Views

Calculo 2 De dos variables_9na Edición - Ron Larson

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

SECCIÓN 14.2 Integrales dobles y volumen 1003

Probabilidad

Una función de densidad de probabilidad conjunta

de las variables aleatorias continuas x y y es una función

ƒ(x, y) que satisface las propiedades siguientes.

a) para todo b)

c)

En los ejercicios 73 a 76, mostrar que la función es una función

de densidad de probabilidad conjunta y hallar la probabilidad

requerida.

73.

74.

75.

76.

77. Aproximación En una fábrica de cemento la base de un montón

de arena es rectangular con dimensiones aproximadas de 20

por 30 metros. Si la base se coloca en el plano xy con un vértice

en el origen, las coordenadas de la superficie del montón son

(5, 5, 3), (15, 5, 6), (25, 5, 4), (5, 15, 2), (15, 15, 7) y (25, 15, 3).

Aproximar el volumen de la arena en el montón.

78. Programación Considerar una función continua sobre

la región rectangular R con vértices (a, c), (b, c), (a, d) y (b, d)

donde y Dividir los intervalos y en

y

subintervalos, de modo que los subintervalos en una dirección

dada sean de igual longitud. Escribir un programa para que

una herramienta de graficación calcule la suma

donde

es el centro de un rectángulo representativo en

Aproximación

En los ejercicios 79 a 82, a) utilizar un sistema

algebraico por computadora y aproximar la integral iterada, y

b) utilizar el programa del ejercicio 78 para aproximar la integral

iterada con los valores dados de m y n.

79. 80.

81. 82.

Aproximación

En los ejercicios 83 y 84, determinar qué valor

aproxima mejor el volumen del sólido entre el plano xy y la función

sobre la región. (Hacer la elección con base en un dibujo del sólido

y sin realizar ningún cálculo.)

83.

cuadrado con vértices

a) b) 600 c) 50 d) 125 e) 1 000

84.

círculo acotado por

a) 50 b) 500 c) d) 5 e) 5 000

¿Verdadero o falso?

En los ejercicios 85 y 86, determinar si la

declaración es verdadera o falsa. Si es falsa, explicar por qué o

dar un ejemplo que demuestre que es falsa.

85. El volumen de la esfera está dado por la integral

86. Si para todo en R, y ƒ y g son continuas

en R, entonces

87. Sea Hallar el valor promedio de f en el intervalo

88. Hallar Sugerencia: Evaluar

89. Determinar la región R en el plano xy que maximiza el valor de

90. Determinar la región R en el plano xy que minimiza el valor de

91. Hallar (Sugerencia: Convertir la

integral en una integral doble.)

92. Utilizar un argumento geométrico para mostrar que

3

0

9y 2

0

9 x 2 y 2 dx dy 9

2 .

2 0 arctanx arctan x dx.

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R fx, y dA

R gx, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x uyuy x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R fx, y dA

R gx, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x uyuy x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

2

1

e xy dy.

0

e x e 2x

x

dx.

0, 1.

f x x 1 e t2 dt.

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R f x, y dA

R g x, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x uyuy x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

x, y

f x, y ≤ gx, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

f x, y x 2 y 2

200

0, 0, 4, 0, 4, 4, 0, 4

R:

f x, y 4x

m 6, n 4

m 4, n 8

4

1

2

1

x 3 y 3 dx dy

6

4

2

0

y cos x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sin x y dy dx

R.

x i , y j

n

i1 m

j1

f x i , y j A i

b

a

d

c

f x, y dA

n

m

c, d

a, b

c < d.

a < b

f x, y

P0 ≤ x ≤ 1, x ≤ y ≤ 1

f x, y e xy ,

0,

x ≥ 0, y ≥ 0

elsewhere

P0 ≤ x ≤ 1, 4 ≤ y ≤ 6

f x, y 1

279 x y,

0,

0 ≤ x ≤ 3, 3 ≤ y ≤ 6

elsewhere

P0 ≤ x ≤ 1, 1 ≤ y ≤ 2

f x, y 1

4 xy,

0,

0 ≤ x ≤ 2, 0 ≤ y ≤ 2

elsewhere

P0 ≤ x ≤ 2, 1 ≤ y ≤ 2

f x, y 1

10 ,

0,

0 ≤ x ≤ 5, 0 ≤ y ≤ 2

elsewhere

P[x, y R] R f x, y dA

f x, y dA 1

x, y

f x, y ≥ 0

en cualquier otro punto

en cualquier otro punto

en cualquier otro punto

en cualquier otro punto

Para discusión

72. Las siguientes integrales iteradas representan la solución al

mismo problema. ¿Cuál integral iterada es más fácil de evaluar?

Explicar el razonamiento.

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R fx, y dA

R gx, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x uyuy x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

CAS

Preparación del examen Putnam

93. Evaluar donde a y b son positivos.

94. Probar que si no existe una función real u tal que, para

todo x en el intervalo cerrado ,

Estos problemas fueron preparados por el Committee on the Putnam Prize

Competition. © The Mathematical Association of America. Todos los derechos reservados.

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x 2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R fx, y dA

R gx, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

S

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x u y u y x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79.

81.

Approximation In Exercises 83

best approximates the volume of

and the function over the region

basis of a sketch of the solid

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50

84.

circle bounded by

(a) 50 (b) 500 (c)

True or False?

In Exercises 85 a

statement is true or false. If it is

example that shows it is false.

85. The volume of the sphere

integral

86. If for all

continuous over

then

87. Let Find the a

88. Find

89. Determine the region in th

value of

90. Determine the region in th

value of

91. Find

to a double integral.)

92. Use a geometric argument to s

3

0

9 y 2

0

9 x 2 y 2 dx d

2

0 arctan x arctan x

R x2 y 2 4 dA.

R

R 9 x2 y 2 dA.

R

0

e x

e 2x

x

dx.

0, 1 .

f x

x

1 e t2 dt.

R fx

R, x,

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx

x 2

500

x 2 y 2

R:

fx, y x 2 y 2

200

0, 0 ,

R:

fx, y

4x

m 4, n 8

6

4

2

0

y cos

x dx dy

m 4, n 8

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

fx, y

y

x

14.2 Double In

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate

positive.

94. Show that if there doe

tion such that for all in t

These problems were composed by th

Competition. © The Mathematical Associa

u x 1

1

x uyuy

x

x

u

> 1 2

a

0 b

0 emax b2 x 2 , a 2 y 2

PUTNAM EXAM CHALLEN

0 ≤ x ≤ 1

> 1 2

Probability

A joint density function of the continuous random

variables and is a function satisfying the following

properties.

(a) for all (b)

(c)

In Exercises 73–76, show that the function is a joint density

function and find the required probability.

73.

74.

75.

76.

77. Approximation The base of a pile of sand at a cement plant is

rectangular with approximate dimensions of 20 meters by

30 meters. If the base is placed on the plane with one vertex

at the origin, the coordinates on the surface of the pile are

and

Approximate the volume of sand in the pile.

78. Programming Consider a continuous function over

the rectangular region with vertices and

where and Partition the intervals and

into and subintervals, so that the subintervals in a

given direction are of equal length. Write a program for a

graphing utility to compute the sum

where

is the center of a representative rectangle in

Approximation

In Exercises 79–82, (a) use a computer algebra

system to approximate the iterated integral, and (b) use the

program in Exercise 78 to approximate the iterated integral for

the given values of

and

79. 80.

81. 82.

Approximation

In Exercises 83 and 84, determine which value

best approximates the volume of the solid between the

-plane

and the function over the region. (Make your selection on the

basis of a sketch of the solid and not by performing any

calculations.)

83.

square with vertices

(a) (b) 600 (c) 50 (d) 125 (e) 1000

84.

circle bounded by

(a) 50 (b) 500 (c) (d) 5 (e) 5000

True or False?

In Exercises 85 and 86, determine whether the

statement is true or false. If it is false, explain why or give an

example that shows it is false.

85. The volume of the sphere is given by the

integral

86. If for all in and both and are

continuous over

then

87. Let Find the average value of on the interval

88. Find Hint: Evaluate

89. Determine the region in the -plane that maximizes the

value of

90. Determine the region in the -plane that minimizes the

value of

91. Find (Hint: Convert the integral

to a double integral.)

92. Use a geometric argument to show that

3

0

9 y 2

0

9 x 2 y 2 dx dy

9

2 .

2

0 arctan x arctan x dx.

R x2 y 2 4 dA.

xy

R

R 9 x2 y 2 dA.

xy

R

2

1

e xy dy.

0

e x

e 2x

x

dx.

0, 1 .

f

f x

x

1 e t2 dt.

R fx, y dA

R gx, y dA.

R, g

f

R,

x, y

f x, y

g x, y

V 8

1

0

1

0

1 x 2 y 2 dx dy.

x 2 y 2 z 2 1

500

x 2 y 2 9

R:

fx, y x 2 y 2

200

0, 0 , 4, 0 , 4, 4 , 0, 4

R:

fx, y

4x

xy

m 6, n 4

m 4, n 8

4

1

2

1

x 3

y 3 dx dy

6

4

2

0

y cos

x dx dy

m 10, n 20

m 4, n 8

2

0

4

0

20e x3 8 dy dx

1

0

2

0

sen x y dy dx

n.

m

R.

x i , y j

n

i 1

m

j 1

fx i , y j A i b

a

d

c

fx, y dA

n

m

c, d

a, b

c < d.

a < b

b, d ,

a, d ,

b, c ,

a, c ,

R

fx, y

25, 15, 3 .

15, 15, 7 ,

5, 15, 2 ,

25, 5, 4 ,

15, 5, 6 ,

5, 5, 3 ,

xy-

P 0 x 1, x y 1

fx, y

e x y ,

0,

x 0, y 0

elsewhere

P 0 x 1, 4 y 6

fx, y

1

27 9 x y ,

0,

0 x 3, 3 y 6

elsewhere

P 0 x 1, 1 y 2

fx, y

1

4 xy,

0,

0 x 2, 0 y 2

elsewhere

P 0 x 2, 1 y 2

fx, y

1

10 ,

0,

0 x 5, 0 y 2

elsewhere

P[ x, y R]

R

fx, y dA

fx, y dA 1

x, y

f x, y ~ 0

f x, y

y

x

14.2 Double Integrals and Volume 1003

72. The following iterated integrals represent the solution to the

same problem. Which iterated integral is easier to evaluate?

Explain your reasoning.

4

0

2

x 2

sen y 2 dy dx

2

0

2y

0

sen y 2 dx dy

CAPSTONE

CAS

93. Evaluate where and are

positive.

94. Show that if there does not exist a real-valued function

such that for all in the closed interval

These problems were composed by the Committee on the Putnam Prize

Competition. © The Mathematical Association of America. All rights reserved.

ux 1

1

x uyuy x dy. 0 x 1,

x

u

> 1 2

b

a

a

0 b

0 emax b2 x 2 , a 2 y 2 dy dx,

PUTNAM EXAM CHALLENGE

e máx

sen

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!