Mathematical Excursions (MindTap Course List)
4th Edition
ISBN: 9781305965584
Author: Richard N. Aufmann, Joanne Lockwood, Richard D. Nation, Daniel K. Clegg
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 2, Problem 24RE
To determine
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Evaluate the following integrals, showing all your working
Differentiate the following function
Differentiate the following function
Chapter 2 Solutions
Mathematical Excursions (MindTap Course List)
Ch. 2.1 - Mark, Erica, Larry, and Jennifer have each defined...Ch. 2.1 - In some fuzzy sets, membership values are given by...Ch. 2.1 - The following membership graph provides a...Ch. 2.1 - The membership graphs in the following figure...Ch. 2.1 - The membership graph in Excursion Exercise 2 shows...Ch. 2.1 - Prob. 1ESCh. 2.1 - Prob. 2ESCh. 2.1 - Prob. 3ESCh. 2.1 - Prob. 4ESCh. 2.1 - Prob. 5ES
Ch. 2.1 - Prob. 6ESCh. 2.1 - Prob. 7ESCh. 2.1 - Prob. 8ESCh. 2.1 - Prob. 9ESCh. 2.1 - Prob. 10ESCh. 2.1 - Prob. 11ESCh. 2.1 - Prob. 12ESCh. 2.1 - In Exercises I to 14, use the roster method to...Ch. 2.1 - Prob. 14ESCh. 2.1 - Prob. 15ESCh. 2.1 - In Exercises 15 to 24, write a word description of...Ch. 2.1 - In Exercises 15 to 24, write a word description of...Ch. 2.1 - In Exercises 15 to 24, write a word description of...Ch. 2.1 - Prob. 19ESCh. 2.1 - Prob. 20ESCh. 2.1 - Prob. 21ESCh. 2.1 - Prob. 22ESCh. 2.1 - Prob. 23ESCh. 2.1 - Prob. 24ESCh. 2.1 - In Exercises 25 to 36, determine whether each...Ch. 2.1 - Prob. 26ESCh. 2.1 - Prob. 27ESCh. 2.1 - Prob. 28ESCh. 2.1 - Prob. 29ESCh. 2.1 - In Exercises 25 to 36, determine whether each...Ch. 2.1 - Prob. 31ESCh. 2.1 - Prob. 32ESCh. 2.1 - Prob. 33ESCh. 2.1 - Prob. 34ESCh. 2.1 - Prob. 35ESCh. 2.1 - Prob. 36ESCh. 2.1 - Prob. 37ESCh. 2.1 - Prob. 38ESCh. 2.1 - Prob. 39ESCh. 2.1 - Prob. 40ESCh. 2.1 - In Exercises 37 to 48, use set-builder notation to...Ch. 2.1 - Prob. 42ESCh. 2.1 - Prob. 43ESCh. 2.1 - Prob. 44ESCh. 2.1 - Prob. 45ESCh. 2.1 - Prob. 46ESCh. 2.1 - Prob. 47ESCh. 2.1 - Prob. 48ESCh. 2.1 - Prob. 49ESCh. 2.1 - Prob. 50ESCh. 2.1 - Prob. 51ESCh. 2.1 - Prob. 52ESCh. 2.1 - Prob. 53ESCh. 2.1 - Prob. 54ESCh. 2.1 - Prob. 55ESCh. 2.1 - Prob. 56ESCh. 2.1 - Prob. 57ESCh. 2.1 - Prob. 58ESCh. 2.1 - Prob. 59ESCh. 2.1 - Prob. 60ESCh. 2.1 - Prob. 61ESCh. 2.1 - Prob. 62ESCh. 2.1 - Prob. 63ESCh. 2.1 - In Exercises 63 to 70, state whether each of the...Ch. 2.1 - In Exercises 63 to 70, state whether each of the...Ch. 2.1 - Prob. 66ESCh. 2.1 - Prob. 67ESCh. 2.1 - Prob. 68ESCh. 2.1 - Prob. 69ESCh. 2.1 - Prob. 70ESCh. 2.1 - Prob. 71ESCh. 2.1 - Prob. 72ESCh. 2.1 - Prob. 73ESCh. 2.1 - Prob. 74ESCh. 2.1 - Prob. 75ESCh. 2.1 - Prob. 76ESCh. 2.1 - Prob. 77ESCh. 2.1 - Prob. 78ESCh. 2.1 - Prob. 79ESCh. 2.1 - Prob. 80ESCh. 2.1 - Prob. 81ESCh. 2.1 - Prob. 82ESCh. 2.1 - In Exercises 83 to 86, use the extension of...Ch. 2.1 - Prob. 84ESCh. 2.1 - Prob. 85ESCh. 2.1 - Prob. 86ESCh. 2.1 - Prob. 87ESCh. 2.1 - Prob. 88ESCh. 2.1 - Prob. 89ESCh. 2.1 - Prob. 90ESCh. 2.2 - Let K = {(1, 0.4), (2, 0.6), (3,0.8), (4, 1)) and...Ch. 2.2 - Prob. 2EECh. 2.2 - Prob. 3EECh. 2.2 - Prob. 4EECh. 2.2 - Prob. 5EECh. 2.2 - Prob. 1ESCh. 2.2 - Prob. 2ESCh. 2.2 - Prob. 3ESCh. 2.2 - Prob. 4ESCh. 2.2 - Prob. 5ESCh. 2.2 - Prob. 6ESCh. 2.2 - Prob. 7ESCh. 2.2 - Prob. 8ESCh. 2.2 - Prob. 9ESCh. 2.2 - Prob. 10ESCh. 2.2 - Prob. 11ESCh. 2.2 - Prob. 12ESCh. 2.2 - Prob. 13ESCh. 2.2 - Prob. 14ESCh. 2.2 - Prob. 15ESCh. 2.2 - Prob. 16ESCh. 2.2 - Prob. 17ESCh. 2.2 - Prob. 18ESCh. 2.2 - Prob. 19ESCh. 2.2 - Prob. 20ESCh. 2.2 - Prob. 21ESCh. 2.2 - Prob. 22ESCh. 2.2 - Prob. 23ESCh. 2.2 - Prob. 24ESCh. 2.2 - Prob. 25ESCh. 2.2 - Prob. 26ESCh. 2.2 - Prob. 27ESCh. 2.2 - Prob. 28ESCh. 2.2 - Prob. 29ESCh. 2.2 - Prob. 30ESCh. 2.2 - Prob. 31ESCh. 2.2 - Prob. 32ESCh. 2.2 - Prob. 33ESCh. 2.2 - Prob. 34ESCh. 2.2 - Prob. 35ESCh. 2.2 - Prob. 36ESCh. 2.2 - Prob. 37ESCh. 2.2 - Prob. 38ESCh. 2.2 - Prob. 39ESCh. 2.2 - Prob. 40ESCh. 2.2 - Prob. 41ESCh. 2.2 - Prob. 42ESCh. 2.2 - Prob. 43ESCh. 2.2 - Prob. 44ESCh. 2.2 - Prob. 45ESCh. 2.2 - Prob. 46ESCh. 2.2 - Prob. 47ESCh. 2.2 - Prob. 48ESCh. 2.2 - Prob. 49ESCh. 2.2 - Prob. 50ESCh. 2.2 - Prob. 51ESCh. 2.2 - In Exercises 47 to 54, find the number of subsets...Ch. 2.2 - Prob. 53ESCh. 2.2 - Prob. 54ESCh. 2.2 - Suppose you have a nickel, two dimes, and a...Ch. 2.2 - Prob. 56ESCh. 2.2 - Sandwich Choices A delicatessen makes a...Ch. 2.2 - Upgrade Options A company that builds homes...Ch. 2.2 - Omelet Choices A restaurant provides a brunch...Ch. 2.2 - Truck Options A truck company makes a pickup truck...Ch. 2.2 - Prob. 61ESCh. 2.2 - Prob. 62ESCh. 2.2 - Voting Coalitions Five people, designated A, B, C,...Ch. 2.2 - Prob. 64ESCh. 2.3 - En Excursion Exercise I of Section 2.1, we defined...Ch. 2.3 - En Excursion Exercise I of Section 2.1, we defined...Ch. 2.3 - Prob. 3EECh. 2.3 - En Excursion Exercise I of Section 2.1, we defined...Ch. 2.3 - Prob. 5EECh. 2.3 - Prob. 6EECh. 2.3 - Prob. 7EECh. 2.3 - Prob. 1ESCh. 2.3 - Prob. 2ESCh. 2.3 - Prob. 3ESCh. 2.3 - Prob. 4ESCh. 2.3 - Prob. 5ESCh. 2.3 - Prob. 6ESCh. 2.3 - Prob. 7ESCh. 2.3 - Prob. 8ESCh. 2.3 - Prob. 9ESCh. 2.3 - Prob. 10ESCh. 2.3 - Prob. 11ESCh. 2.3 - Prob. 12ESCh. 2.3 - Prob. 13ESCh. 2.3 - Prob. 14ESCh. 2.3 - Prob. 15ESCh. 2.3 - Prob. 16ESCh. 2.3 - Prob. 17ESCh. 2.3 - Prob. 18ESCh. 2.3 - Prob. 19ESCh. 2.3 - Prob. 20ESCh. 2.3 - Prob. 21ESCh. 2.3 - Prob. 22ESCh. 2.3 - Prob. 23ESCh. 2.3 - Prob. 24ESCh. 2.3 - In Exercises 21 to 28, write a sentence that...Ch. 2.3 - Prob. 26ESCh. 2.3 - Prob. 27ESCh. 2.3 - Prob. 28ESCh. 2.3 - Prob. 29ESCh. 2.3 - Prob. 30ESCh. 2.3 - Prob. 31ESCh. 2.3 - Prob. 32ESCh. 2.3 - Prob. 33ESCh. 2.3 - Prob. 34ESCh. 2.3 - Prob. 35ESCh. 2.3 - Prob. 36ESCh. 2.3 - Prob. 37ESCh. 2.3 - Prob. 38ESCh. 2.3 - Prob. 39ESCh. 2.3 - Prob. 40ESCh. 2.3 - Prob. 41ESCh. 2.3 - Prob. 42ESCh. 2.3 - Prob. 43ESCh. 2.3 - Prob. 44ESCh. 2.3 - Prob. 45ESCh. 2.3 - Prob. 46ESCh. 2.3 - Prob. 47ESCh. 2.3 - Prob. 48ESCh. 2.3 - Prob. 49ESCh. 2.3 - Subtractive Color Mixing Artists who paint with...Ch. 2.3 - Prob. 51ESCh. 2.3 - Subtractive Color Mixing Artists who paint with...Ch. 2.3 - Prob. 53ESCh. 2.3 - Prob. 54ESCh. 2.3 - Prob. 55ESCh. 2.3 - Prob. 56ESCh. 2.3 - Prob. 57ESCh. 2.3 - Prob. 58ESCh. 2.3 - Prob. 59ESCh. 2.3 - Prob. 60ESCh. 2.3 - Prob. 61ESCh. 2.3 - Prob. 62ESCh. 2.3 - A Survey Aspecial interest group plans to conduct...Ch. 2.3 - A Music Survey Theadministrators of an Internet...Ch. 2.3 - Prob. 65ESCh. 2.3 - Prob. 66ESCh. 2.3 - Prob. 67ESCh. 2.3 - Prob. 68ESCh. 2.3 - Prob. 69ESCh. 2.3 - Prob. 70ESCh. 2.3 - Prob. 71ESCh. 2.3 - Prob. 72ESCh. 2.3 - Prob. 73ESCh. 2.3 - Prob. 74ESCh. 2.3 - Prob. 75ESCh. 2.3 - Prob. 76ESCh. 2.3 - Prob. 77ESCh. 2.3 - Prob. 78ESCh. 2.3 - Prob. 79ESCh. 2.3 - In an article in New Scientist magazine, Anthony...Ch. 2.4 - A selection committee consists of Ryan, Susan. and...Ch. 2.4 - A selection committee consists of three people...Ch. 2.4 - Determine the minimal winning coalitions for the...Ch. 2.4 - Prob. 1ESCh. 2.4 - Prob. 2ESCh. 2.4 - In Exercises I to 10, let U = English, French,...Ch. 2.4 - Prob. 4ESCh. 2.4 - Prob. 5ESCh. 2.4 - Prob. 6ESCh. 2.4 - In Exercises I to 10, let U = English, French,...Ch. 2.4 - Prob. 8ESCh. 2.4 - Prob. 9ESCh. 2.4 - Prob. 10ESCh. 2.4 - Prob. 11ESCh. 2.4 - Prob. 12ESCh. 2.4 - Prob. 13ESCh. 2.4 - Prob. 14ESCh. 2.4 - Prob. 15ESCh. 2.4 - Given n(A) = 640, n(B) = 280, and n(A U B) = 765,...Ch. 2.4 - Prob. 17ESCh. 2.4 - In Exercises 17 and 18, use the given information...Ch. 2.4 - In a surveyof 600 investors, it was reported that...Ch. 2.4 - Commuting A survey of 1500 commuters in New York...Ch. 2.4 - A team physician has determined that of all the...Ch. 2.4 - The management of a hotel conducted a survey. ft...Ch. 2.4 - A computer company advertises its computers in PC...Ch. 2.4 - During one month, a blood donation center found...Ch. 2.4 - A special interest group has conducted a survey...Ch. 2.4 - A survey of college students was taken to...Ch. 2.4 - A survey was completed by individuals who were...Ch. 2.4 - Prob. 28ESCh. 2.4 - Prob. 29ESCh. 2.4 - Prob. 30ESCh. 2.4 - Prob. 31ESCh. 2.4 - Prob. 32ESCh. 2.5 - Use two disjoint sets to show that 0+2=0.Ch. 2.5 - Prob. 2EECh. 2.5 - Use sets toshow that 06=0.Ch. 2.5 - Prob. 1ESCh. 2.5 - Establish a one-to-one correspondence between the...Ch. 2.5 - Establish a one-to-one correspondence between D =...Ch. 2.5 - Prob. 4ESCh. 2.5 - Prob. 5ESCh. 2.5 - In Exercises 4 to 10, state the cardinality of...Ch. 2.5 - Prob. 7ESCh. 2.5 - Prob. 8ESCh. 2.5 - Prob. 9ESCh. 2.5 - Prob. 10ESCh. 2.5 - Prob. 11ESCh. 2.5 - In Exercises 11 to 14, determine whether the given...Ch. 2.5 - Prob. 13ESCh. 2.5 - Prob. 14ESCh. 2.5 - Prob. 15ESCh. 2.5 - In Exercises 15 to 18, show that the given set is...Ch. 2.5 - Prob. 17ESCh. 2.5 - Prob. 18ESCh. 2.5 - In Exercises 19 to 26, show that the given set has...Ch. 2.5 - Prob. 20ESCh. 2.5 - Prob. 21ESCh. 2.5 - In Exercises 19 to 26, show that the given set has...Ch. 2.5 - Prob. 23ESCh. 2.5 - In Exercises 19 to 26, show that the given set has...Ch. 2.5 - In Exercises 19 to 26, show that the given set has...Ch. 2.5 - In Exercises 19 to 26, show that the given set has...Ch. 2.5 - Prob. 27ESCh. 2.5 - Prob. 28ESCh. 2.5 - Prob. 29ESCh. 2.5 - The Hubert Hotel is an imaginary hotel created by...Ch. 2 - Prob. 1RECh. 2 - In Exercises 1 to 6, use the roster method to...Ch. 2 - Prob. 3RECh. 2 - Prob. 4RECh. 2 - Prob. 5RECh. 2 - Prob. 6RECh. 2 - Prob. 7RECh. 2 - Prob. 8RECh. 2 - Prob. 9RECh. 2 - Prob. 10RECh. 2 - Prob. 11RECh. 2 - Prob. 12RECh. 2 - Prob. 13RECh. 2 - Prob. 14RECh. 2 - Prob. 15RECh. 2 - Prob. 16RECh. 2 - Prob. 17RECh. 2 - Prob. 18RECh. 2 - Prob. 19RECh. 2 - Prob. 20RECh. 2 - Prob. 21RECh. 2 - Prob. 22RECh. 2 - Prob. 23RECh. 2 - Prob. 24RECh. 2 - Prob. 25RECh. 2 - Prob. 26RECh. 2 - Prob. 27RECh. 2 - Prob. 28RECh. 2 - Prob. 29RECh. 2 - Prob. 30RECh. 2 - Prob. 31RECh. 2 - Prob. 32RECh. 2 - Prob. 33RECh. 2 - Prob. 34RECh. 2 - Prob. 35RECh. 2 - Prob. 36RECh. 2 - In Exercises 35 to 38, find the number of subsets...Ch. 2 - Prob. 38RECh. 2 - Prob. 39RECh. 2 - Prob. 40RECh. 2 - Prob. 41RECh. 2 - Prob. 42RECh. 2 - Prob. 43RECh. 2 - Prob. 44RECh. 2 - Prob. 45RECh. 2 - Prob. 46RECh. 2 - Prob. 47RECh. 2 - Prob. 48RECh. 2 - Prob. 49RECh. 2 - Prob. 50RECh. 2 - Prob. 51RECh. 2 - Prob. 52RECh. 2 - In a survey at a health club, 208 members...Ch. 2 - A gourmet coffee bar conducted a survey to...Ch. 2 - Prob. 55RECh. 2 - Prob. 56RECh. 2 - Prob. 57RECh. 2 - Prob. 58RECh. 2 - Prob. 59RECh. 2 - Prob. 60RECh. 2 - Prob. 61RECh. 2 - Prob. 62RECh. 2 - Prob. 63RECh. 2 - Prob. 64RECh. 2 - Prob. 65RECh. 2 - Prob. 66RECh. 2 - Prob. 67RECh. 2 - Prob. 68RECh. 2 - Prob. 69RECh. 2 - Prob. 70RECh. 2 - Prob. 71RECh. 2 - Prob. 72RECh. 2 - Prob. 1TCh. 2 - Prob. 2TCh. 2 - Prob. 3TCh. 2 - Prob. 4TCh. 2 - Prob. 5TCh. 2 - Prob. 6TCh. 2 - Prob. 7TCh. 2 - Prob. 8TCh. 2 - Prob. 9TCh. 2 - Prob. 10TCh. 2 - Prob. 11TCh. 2 - Prob. 12TCh. 2 - Prob. 13TCh. 2 - Prob. 14TCh. 2 - Upgrade Options An automobile company makes a...Ch. 2 - Student Demographics A college finds that 841 of...Ch. 2 - The following bar graph shows the monthly...Ch. 2 - A survey of 1000 households was taken to determine...Ch. 2 - Show a method that can be used to establish a...Ch. 2 - Prob. 20T
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, subject and related others by exploring similar questions and additional content below.Similar questions
- A box with a square base and open top must have a volume of 13,500 cm³. Find the dimensions that minimise the amount of material used. Ensure you show your working to demonstrate that it is a minimum.arrow_forwardConsider the equation, f(x) = x*. (a) Using the trapezoidal method with 3 columns, estimate the value of the integral f² f(x)dx. (b) Using the trapezoidal method with 10 columns, estimate the value of the integral f² f(x)dx. You many need software to help you do this (e.g. MATLAB, Excel, Google sheets). (c) Use software to accurately calculate the integral (e.g. Wolfram alpha, Matlab). Using this answer, comment on the answers you found in parts a) and b).arrow_forwardUsing the first-principles definition of differentiation, find the derivative of f(x) = = 2x²arrow_forward
- Evaluate the following integrals, showing all your workingarrow_forwardDifferentiate the following functionarrow_forward2. You manage a chemical company with 2 warehouses. The following quantities of Important Chemical A have arrived from an international supplier at 3 different ports: Chemical Available (L) Port 1. 400 Port 2 110 Port 3 100 The following amounts of Important Chemical A are required at your warehouses: Warehouse 1 Warehouse 2 Chemical Required (L) 380 230 The cost in £ to ship 1L of chemical from each port to each warehouse is as follows: Warehouse 1 Warehouse 2 Port 1 £10 £45 Port 2 £20 £28 Port 3 £13 £11 (a) You want to know how to send these shipments as cheaply as possible. For- mulate this as a linear program (you do not need to formulate it in standard inequality form). (b) Suppose now that all is as in the previous question but that only 320L of Important Chemical A are now required at Warehouse 1. Any excess chemical can be transported to either Warehouse 1 or 2 for storage, in which case the company must pay only the relevant transportation costs, or can be disposed of at the…arrow_forward
- choose true options in these from given question a) always full and always crossing. b) always full and sometimes crossing. c) always full and never crossing. d) sometimes full and always crossing. e) sometimes full and sometimes crossing. f) sometimes full and never crossing. g) never full and always crossing. h) never full and sometimes crossing. i) never full and never crossing.arrow_forwardAt a Noodles & Company restaurant, the probability that a customer will order a nonalcoholic beverage is 0.49. Find the probability that in a sample of 13 customers, at least 7 will order a nonalcoholic beveragearrow_forward10. In the general single period market model with = {W1, W2, W3}, one risky asset, S, and a money market account, we have So = 4 for the risky asset. Moreover, the effective rate of interest on the money market account is 5% and at time t = 1 we have W1 W2 W3 S₁ 100 50 40 21 21 21 (a) Calculate all risk-neutral probability measures for this model. [4 Marks] (b) State if the model is arbitrage-free. Give a brief reason for your answer. [2 Marks] (c) A large bank has designed an investment product with payoff X at time t = 1. Given W₁ W2 W3 X 0 1 1.5 show that X is an attainable contingent claim. [4 marks]arrow_forward
- Question 1. (10 points) A researcher is studying tumours in mice. The growth rate for the volume of the tumour V(t) in cm³ is given by dV = 1.45V(2 In(V+1)). dt (a) (4 pts) Find all the equilibria and determine their stability using the stability condition. (b) (2 pts) Draw the phase plot f(V) versus V where f(V) = V'. You may find it helpful to use Desmos or Wolfram Alpha to plot the graph of f(V) versus V (both are free to use online), or you can plot it by hand if you like. On the plot identify each equilibrium as stable or unstable. (c) (4 pts) Draw direction arrows for the case where the tumour starts at size 3cm³ and for the case where the tumour starts at size 9cm³. Explain in biological terms what happens to the size of each of these tumours at time progresses.arrow_forwardFor the system consisting of the two planes:plane 1: -x + y + z = 0plane 2: 3x + y + 3z = 0a) Are the planes parallel and/or coincident? Justify your answer. What does this tell you about the solution to the system?b) Solve the system (if possible). Show a complete solution. If there is a line of intersection express it in parametric form.arrow_forwardadded 2 imagesarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage
Elementary Geometry For College Students, 7eGeometryISBN:9781337614085Author:Alexander, Daniel C.; Koeberlein, Geralyn M.Publisher:Cengage,
Algebra: Structure And Method, Book 1AlgebraISBN:9780395977224Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. ColePublisher:McDougal Littell
Elements Of Modern AlgebraAlgebraISBN:9781285463230Author:Gilbert, Linda, JimmiePublisher:Cengage Learning,
Elementary Linear Algebra (MindTap Course List)AlgebraISBN:9781305658004Author:Ron LarsonPublisher:Cengage Learning
Trigonometry (MindTap Course List)TrigonometryISBN:9781305652224Author:Charles P. McKeague, Mark D. TurnerPublisher:Cengage Learning
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage
Elementary Geometry For College Students, 7e
Geometry
ISBN:9781337614085
Author:Alexander, Daniel C.; Koeberlein, Geralyn M.
Publisher:Cengage,
Algebra: Structure And Method, Book 1
Algebra
ISBN:9780395977224
Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. Cole
Publisher:McDougal Littell
Elements Of Modern Algebra
Algebra
ISBN:9781285463230
Author:Gilbert, Linda, Jimmie
Publisher:Cengage Learning,
Elementary Linear Algebra (MindTap Course List)
Algebra
ISBN:9781305658004
Author:Ron Larson
Publisher:Cengage Learning
Trigonometry (MindTap Course List)
Trigonometry
ISBN:9781305652224
Author:Charles P. McKeague, Mark D. Turner
Publisher:Cengage Learning