Mathematics with Applications In the Management, Natural, and Social Sciences (12th Edition)
Mathematics with Applications In the Management, Natural, and Social Sciences (12th Edition)
12th Edition
ISBN: 9780134767628
Author: Margaret L. Lial, Thomas W. Hungerford, John P. Holcomb, Bernadette Mullins
Publisher: PEARSON
bartleby

Concept explainers

Equations and Inequations
Equations and inequalities describe the relationship between two mathematical expressions.
Linear Functions
A linear function can just be a constant, or it can be the constant multiplied with the variable like x or y. If the variables are of the form, x2, x1/2 or y2 it is not linear. The exponent over the variables should always be 1.
bartleby

Videos

Question
Book Icon
Chapter 3.3, Problem 1CP
To determine

The rule of the linear cost function.

Expert Solution & Answer
Check Mark

Want to see the full answer?

Check out a sample textbook solution
Blurred answer
Previous
Chapter 3.2, Problem 52E
Next
Chapter 3.3, Problem 2CP

Chapter 3 Solutions

Mathematics with Applications In the Management, Natural, and Social Sciences (12th Edition)

Ch. 3.1 - Checkpoint 1 Find the domain and range of the...Ch. 3.1 - Checkpoint 2 Do the following define...Ch. 3.1 - Checkpoint 3 Do the following define y as a...Ch. 3.1 - Checkpoint 4 Give the domain of each...Ch. 3.1 - Checkpoint 5 Let Find the...Ch. 3.1 - Prob. 6CPCh. 3.1 - Prob. 7CPCh. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...
Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - For each of the following rules, state whether it...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - Prob. 13ECh. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - State the domain of each function. (See Example...Ch. 3.1 - For each of the following functions,...Ch. 3.1 - For each of the following functions,...Ch. 3.1 - For each of the following functions,...Ch. 3.1 - For each of the following functions,...Ch. 3.1 - Prob. 28ECh. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - Prob. 29ECh. 3.1 - Prob. 30ECh. 3.1 - Prob. 31ECh. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (a)...Ch. 3.1 - For each of the following functions, find (a)....Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (See...Ch. 3.1 - For each of the following functions, find f(p);...Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find (a) (b)...Ch. 3.1 - For each of the following functions, find the...Ch. 3.1 - For each of the following functions, find the...Ch. 3.1 - For each of the following functions, find the...Ch. 3.1 - For each of the following functions, find the...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Prob. 55ECh. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Use a calculator to work these exercises. (See...Ch. 3.1 - Prob. 58ECh. 3.1 - Use the table feature of a graphing calculator to...Ch. 3.1 - Use the table feature of a graphing calculator to...Ch. 3.2 - Checkpoint 1 Graph g(x)=35x.Ch. 3.2 - Checkpoint 2 Graph Ch. 3.2 - Checkpoint 3 Graph f(x)={2x3ifx1x2ifx1.Ch. 3.2 - Checkpoint 4 Graph each function. f(x)=|x4|...Ch. 3.2 - Prob. 5CPCh. 3.2 - Checkpoint 6 Graph y=[12x+1].Ch. 3.2 - Prob. 7CPCh. 3.2 - Prob. 8CPCh. 3.2 - Prob. 9CPCh. 3.2 - Graph each function. (See Examples 1–4.) 1. Ch. 3.2 - Graph each function. (See Examples 1–4.) 2. Ch. 3.2 - Graph each function. (See Examples 1–4.) 3. Ch. 3.2 - Graph each function. (See Examples 1–4.) 4. Ch. 3.2 - Graph each function. (See Examples 1–4.) 5. Ch. 3.2 - Graph each function. (See Examples 1–4.) 6. Ch. 3.2 - Prob. 7ECh. 3.2 - Prob. 8ECh. 3.2 - Prob. 9ECh. 3.2 - Graph each function. (See Examples 1–4.) 10. Ch. 3.2 - Graph each function. (See Examples 1–4.) 11. Ch. 3.2 - Graph each function. (See Examples 1–4.) 12. Ch. 3.2 - Graph each function. (See Examples 1–4.) 13. Ch. 3.2 - Graph each function. (See Examples 1–4.) 14. Ch. 3.2 - Graph each function. (See Examples 1–4.) 15. Ch. 3.2 - Prob. 16ECh. 3.2 - Prob. 17ECh. 3.2 - Prob. 18ECh. 3.2 - Prob. 19ECh. 3.2 - Prob. 20ECh. 3.2 - Prob. 21ECh. 3.2 - Postal Rates Theaccompanying table gives rates...Ch. 3.2 - Prob. 23ECh. 3.2 - Prob. 24ECh. 3.2 - Graph each function. (See Examples 7–9.) 31. Ch. 3.2 - Graph each function. (See Examples 7–9.) 32. Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Determine whether each graph is a graph of a...Ch. 3.2 - Use a graphing calculator or other technology to...Ch. 3.2 - Prob. 34ECh. 3.2 - Prob. 35ECh. 3.2 - Prob. 36ECh. 3.2 - Work these exercise. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercise. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - See Examples 2, 3, 10 and 11 as you do Exercises...Ch. 3.2 - Prob. 41ECh. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - Work these exercises. (See Examples 2, 3, 10, and...Ch. 3.2 - Prob. 48ECh. 3.2 - 59. Business Sarah Hendrickson needs to rent a van...Ch. 3.2 - Prob. 50ECh. 3.2 - Prob. 51ECh. 3.2 - Prob. 52ECh. 3.3 - Checkpoint 1 The total cost of producing 10...Ch. 3.3 - Prob. 2CPCh. 3.3 - Prob. 3CPCh. 3.3 - Prob. 4CPCh. 3.3 - Prob. 5CPCh. 3.3 - Prob. 6CPCh. 3.3 - Checkpoint 7 Suppose price and quantity demanded...Ch. 3.3 - Prob. 8CPCh. 3.3 - Business Write a cost function for each of the...Ch. 3.3 - Prob. 2ECh. 3.3 - Prob. 3ECh. 3.3 - Prob. 4ECh. 3.3 - Business Assume that each of the given situations...Ch. 3.3 - Prob. 6ECh. 3.3 - Business Assume that each of the given situations...Ch. 3.3 - Prob. 8ECh. 3.3 - Prob. 9ECh. 3.3 - Prob. 10ECh. 3.3 - Prob. 11ECh. 3.3 - Business In Exercises 9–12, a cost function is...Ch. 3.3 - Business Work these exercises. (See Example...Ch. 3.3 - Prob. 14ECh. 3.3 - Business Work these exercises. (See Example...Ch. 3.3 - Business Work these exercises. (See Example...Ch. 3.3 - Prob. 17ECh. 3.3 - Business Work these problems. (See Example...Ch. 3.3 - Business Work these problems. (See Examples 2 and...Ch. 3.3 - 20. In deciding whether to set up a new...Ch. 3.3 - Business Work these problems. (See Example 5.)...Ch. 3.3 - Business Work these problems. (See Example 5.) Gas...Ch. 3.3 - Business Work these problems. (See Example...Ch. 3.3 - Prob. 24ECh. 3.3 - Prob. 25ECh. 3.3 - Prob. 26ECh. 3.3 - Prob. 27ECh. 3.3 - Prob. 29ECh. 3.3 - Prob. 30ECh. 3.3 - Prob. 31ECh. 3.3 - Prob. 32ECh. 3.3 - Prob. 33ECh. 3.3 - Prob. 34ECh. 3.3 - 35. The revenue (in millions of dollars) from the...Ch. 3.3 - Prob. 36ECh. 3.3 - Prob. 37ECh. 3.3 - Business Suppose you are the manager of a firm....Ch. 3.3 - Business Suppose you are the manager of a firm....Ch. 3.3 - Prob. 40ECh. 3.3 - Prob. 41ECh. 3.3 - Business Suppose you are the manager of a firm....Ch. 3.3 - Prob. 44ECh. 3.3 - Prob. 45ECh. 3.3 - Prob. 46ECh. 3.3 - Prob. 47ECh. 3.3 - Prob. 48ECh. 3.3 - Economics Work the following exercises. (See...Ch. 3.3 - Economics Work the following exercises. (See...Ch. 3.3 - 51. Let the supply and demand for bananas in cents...Ch. 3.3 - Economics Work the following exercises. (See...Ch. 3.3 - Prob. 53ECh. 3.3 - Prob. 54ECh. 3.4 - Checkpoint 1 Graph each quadratic...Ch. 3.4 - Prob. 2CPCh. 3.4 - Prob. 3CPCh. 3.4 - Prob. 4CPCh. 3.4 - Prob. 5CPCh. 3.4 - Prob. 6CPCh. 3.4 - Prob. 1ECh. 3.4 - Prob. 2ECh. 3.4 - The graph of each of the functions in Exercises...Ch. 3.4 - The graph of each of the functions in Exercises...Ch. 3.4 - Without graphing, determine the vertex of the...Ch. 3.4 - Without graphing, determine the vertex of the...Ch. 3.4 - Without graphing, determine the vertex of the...Ch. 3.4 - Without graphing, determine the vertex of the...Ch. 3.4 - Prob. 9ECh. 3.4 - Match each function with its graph, which is one...Ch. 3.4 - Prob. 11ECh. 3.4 - Prob. 12ECh. 3.4 - Prob. 13ECh. 3.4 - Prob. 14ECh. 3.4 - Prob. 15ECh. 3.4 - Prob. 16ECh. 3.4 - Find the rule of a quadratic function whose graph...Ch. 3.4 - Find the rule of a quadratic function whose graph...Ch. 3.4 - Prob. 19ECh. 3.4 - Prob. 20ECh. 3.4 - Without graphing, find the vertex of the parabola...Ch. 3.4 - Prob. 22ECh. 3.4 - Prob. 23ECh. 3.4 - Without graphing, find the vertex of the parabola...Ch. 3.4 - Without graphing, determine the x- and...Ch. 3.4 - Prob. 26ECh. 3.4 - Without graphing, determine the x- and...Ch. 3.4 - Without graphing, determine the x- and...Ch. 3.4 - Prob. 29ECh. 3.4 - Prob. 30ECh. 3.4 - Prob. 31ECh. 3.4 - Graph each parabola and find its vertex and axis...Ch. 3.4 - Work these problems. (See Example...Ch. 3.4 - Work these problems. (See Example 6.) 34. Souvenir...Ch. 3.4 - Work these problems. (See Example 6.) Nerve...Ch. 3.4 - Work these problems. (See Example 6.) Bullet...Ch. 3.4 - Work these problems. (See Example 6.) Automobile...Ch. 3.4 - Work these problems. (See Example...Ch. 3.4 - Use a calculator to work these...Ch. 3.4 - Use a calculator to work these...Ch. 3.4 - 41. Business Suppose the price p of widgets is...Ch. 3.4 - 42. Business The supply function for a commodity...Ch. 3.4 - Business Find the equilibrium quantity and...Ch. 3.4 - Business Find the equilibrium quantity and...Ch. 3.4 - Business Find the equilibrium quantity and...Ch. 3.4 - Business Find the equilibrium quantity and...Ch. 3.4 - Business The revenue function R(x) and the cost...Ch. 3.4 - Business The revenue function R(x) and the cost...Ch. 3.4 - Business The revenue function R(x) and the cost...Ch. 3.4 - Business The revenue function R(x) and the cost...Ch. 3.4 - Business A store owner finds that at a price of...Ch. 3.4 - Business A store owner finds that at a price of ...Ch. 3.4 - Business Work each problem. (See Example 8.) 53. A...Ch. 3.4 - Business Work each problem. (See Example 8.) The...Ch. 3.4 - Business Work each problem. (See Example 8.) 51. A...Ch. 3.4 - Business Work each problem. (See Example...Ch. 3.4 - Business Work each problem. (See Example 8.) 53. A...Ch. 3.4 - Business Work each problem. (See Example...Ch. 3.4 - Prob. 59ECh. 3.4 - Prob. 60ECh. 3.4 - Prob. 61ECh. 3.4 - Prob. 62ECh. 3.4 - Prob. 63ECh. 3.4 - Prob. 64ECh. 3.4 - Prob. 65ECh. 3.4 - Prob. 66ECh. 3.4 - Prob. 67ECh. 3.4 - Prob. 68ECh. 3.5 - Checkpoint 1 Graph Ch. 3.5 - Checkpoint 2 Graph Ch. 3.5 - Checkpoint 3 Find a viewing window on a graphing...Ch. 3.5 - Checkpoint 4 Multiply out the expression for in...Ch. 3.5 - Checkpoint 5 Graph Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - Prob. 2ECh. 3.5 - Prob. 3ECh. 3.5 - Prob. 4ECh. 3.5 - In Exercises 5-8, state whether the graph could...Ch. 3.5 - In Exercises 5-8, state whether the graph could...Ch. 3.5 - In Exercises 5-8, state whether the graph could...Ch. 3.5 - In Exercises 5-8, state whether the graph could...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - In Exercises 9–14, match the given polynomial...Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - 18. Graph each of the given polynomial functions....Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - Graph each of the given polynomial functions. (See...Ch. 3.5 - Work these exercises. Home Depot Revenue The...Ch. 3.5 - Work these exercises. Caterpillar Revenue The...Ch. 3.5 - Work these exercises. Home Depot Costs The cost...Ch. 3.5 - Work these exercises. Caterpillar Costs The cost...Ch. 3.5 - Work these exercises. 25. Home Depot Profit Find...Ch. 3.5 - Work these exercises. Caterpillar Profit Find the...Ch. 3.5 - Prob. 33ECh. 3.5 - Prob. 34ECh. 3.5 - Prob. 35ECh. 3.5 - Prob. 36ECh. 3.5 - Prob. 27ECh. 3.5 - In Exercises 27−31, use a calculator to evaluate...Ch. 3.5 - Prob. 29ECh. 3.5 - Polynomial Models Use a graphing calculator to do...Ch. 3.5 - Polynomial Models Use a graphing calculator to do...Ch. 3.5 - Prob. 32ECh. 3.6 - Checkpoint 1 Graph the following. (a) (b) Ch. 3.6 - Prob. 2CPCh. 3.6 - Prob. 3CPCh. 3.6 - Prob. 4CPCh. 3.6 - Checkpoint 5 Rework Example 5 with the...Ch. 3.6 - Prob. 1ECh. 3.6 - Prob. 2ECh. 3.6 - Prob. 3ECh. 3.6 - Prob. 4ECh. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Prob. 6ECh. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Prob. 10ECh. 3.6 - Prob. 12ECh. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Graph each function. Give the equations of the...Ch. 3.6 - Prob. 14ECh. 3.6 - Prob. 15ECh. 3.6 - Prob. 16ECh. 3.6 - Prob. 18ECh. 3.6 - Prob. 17ECh. 3.6 - Prob. 19ECh. 3.6 - Prob. 20ECh. 3.6 - Prob. 21ECh. 3.6 - Average Cost For Exercises 21 and 22, recall that...Ch. 3.6 - Prob. 23ECh. 3.6 - Work these problems. (See Example 2.) NASA The...Ch. 3.6 - Work these problems. (See Example 2.) Pollution...Ch. 3.6 - Prob. 26ECh. 3.6 - Business Sketch the portion of the graph in...Ch. 3.6 - Prob. 28ECh. 3.6 - Prob. 29ECh. 3.6 - Prob. 30ECh. 3.6 - Prob. 31ECh. 3.6 - Prob. 32ECh. 3 - In Exercises 1–6, state whether the given rule...Ch. 3 - Prob. 2RECh. 3 - Prob. 3RECh. 3 - Prob. 4RECh. 3 - Prob. 5RECh. 3 - Prob. 6RECh. 3 - Prob. 7RECh. 3 - Prob. 8RECh. 3 - Prob. 9RECh. 3 - Prob. 10RECh. 3 - Prob. 11RECh. 3 - Prob. 12RECh. 3 - Graph the functions in Exercises 13–24. 13. Ch. 3 - Prob. 14RECh. 3 - Graph the functions in Exercises 13–24. 15. Ch. 3 - Graph the functions in Exercises 13–24. 16. Ch. 3 - Graph the functions in Exercises 13–24. 17. Ch. 3 - Prob. 18RECh. 3 - Graph the functions in Exercises 13–24. 19. Ch. 3 - Graph the functions in Exercises 13–24. 20. Ch. 3 - Prob. 21RECh. 3 - Prob. 22RECh. 3 - Prob. 24RECh. 3 - Prob. 23RECh. 3 - 25. Business Let be a function that gives the...Ch. 3 - Prob. 26RECh. 3 - Prob. 27RECh. 3 - Prob. 28RECh. 3 - Business In Exercises 29-32, find the following:...Ch. 3 - Business In Exercises 29–32, find...Ch. 3 - Business In Exercises 29–32, find the...Ch. 3 - Business In Exercises 29-32, find the...Ch. 3 - 33. Business The cost of producing x ink...Ch. 3 - 34. Business The cost of producing x laser...Ch. 3 - 35. Business Suppose the demand and price for the...Ch. 3 - Prob. 36RECh. 3 - Without graphing, determine whether each of the...Ch. 3 - Without graphing, determine whether each of the...Ch. 3 - Without graphing, determine whether each of the...Ch. 3 - Without graphing, determine whether each of the...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Graph each of the following quadratic functions,...Ch. 3 - Determine whether the functions in Exercises 49–52...Ch. 3 - Determine whether the functions in Exercises 49–52...Ch. 3 - Determine whether the functions in Exercises 49–52...Ch. 3 - Determine whether the functions in Exercises 49–52...Ch. 3 - Prob. 53RECh. 3 - Prob. 54RECh. 3 - 55. Student Loans Interest rates for subsidized...Ch. 3 - Natural Gas Pricing The price of European natural...Ch. 3 - Netflix Revenue Netflix Inc. reported revenue (in...Ch. 3 - Netflix Revenue Netflix Inc. reported revenue (in...Ch. 3 - Use quadratic regression and the data from...Ch. 3 - 60. Use quadratic regression and the data from...Ch. 3 - Prob. 62RECh. 3 - Prob. 61RECh. 3 - Prob. 63RECh. 3 - Prob. 64RECh. 3 - Prob. 65RECh. 3 - Prob. 66RECh. 3 - Use a graphing calculator to do Exercises 67...Ch. 3 - Use a graphing calculator to do Exercises 67 -70....Ch. 3 - Use a graphing calculator to do Exercises 67...Ch. 3 - Prob. 70RECh. 3 - Prob. 71RECh. 3 - Prob. 72RECh. 3 - Prob. 73RECh. 3 - Prob. 74RECh. 3 - Prob. 75RECh. 3 - Prob. 76RECh. 3 - Prob. 77RECh. 3 - Prob. 78RECh. 3 - Prob. 79RECh. 3 - Prob. 80RECh. 3 - Find the maximum profit and the number of washing...Ch. 3 - 2. Is the quantity of washing machine loads the...Ch. 3 - Based on this information, what price should the...Ch. 3 - Suppose the owner of the laundry has hired your...
Knowledge Booster
Background pattern image
Math
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.
Recommended textbooks for you
Text book image
Discrete Mathematics and Its Applications ( 8th I...
Math
ISBN:9781259676512
Author:Kenneth H Rosen
Publisher:McGraw-Hill Education
Text book image
Mathematics for Elementary Teachers with Activiti...
Math
ISBN:9780134392790
Author:Beckmann, Sybilla
Publisher:PEARSON
Text book image
Calculus Volume 1
Math
ISBN:9781938168024
Author:Strang, Gilbert
Publisher:OpenStax College
Text book image
Thinking Mathematically (7th Edition)
Math
ISBN:9780134683713
Author:Robert F. Blitzer
Publisher:PEARSON
Text book image
Discrete Mathematics With Applications
Math
ISBN:9781337694193
Author:EPP, Susanna S.
Publisher:Cengage Learning,
Text book image
Pathways To Math Literacy (looseleaf)
Math
ISBN:9781259985607
Author:David Sobecki Professor, Brian A. Mercer
Publisher:McGraw-Hill Education
SEE MORE TEXTBOOKS
What is a Linear Equation in One Variable?; Author: Don't Memorise;https://www.youtube.com/watch?v=lDOYdBgtnjY;License: Standard YouTube License, CC-BY
Linear Equation | Solving Linear Equations | What is Linear Equation in one variable ?; Author: Najam Academy;https://www.youtube.com/watch?v=tHm3X_Ta_iE;License: Standard YouTube License, CC-BY