Precalculus
Precalculus
9th Edition
ISBN: 9780321716835
Author: Michael Sullivan
Publisher: Addison Wesley
bartleby

Concept explainers

bartleby

Videos

Textbook Question
Book Icon
Chapter 3.3, Problem 80AYU

Business The daily revenue R achieved by selling x boxes of candy is figured to be R ( x )   =   9.5 x     0.04 x 2 . The daily cost C of selling x boxes of candy is C ( x )   =   1.25 x   +   250 .

(a) How many boxes of candy must the firm sell to maximize revenue? What is the maximum revenue?

(b) Profit is given as P ( x )   =   R ( x )     C ( x ) . What is the profit function?

(c) How many boxes of candy must the firm sell to maximize profit? What is the maximum profit?

(d) Provide a reasonable explanation as to why the answers found in parts ( a )  and  ( c ) differ. Explain why a quadratic function is a reasonable model for revenue.

Expert Solution & Answer
Check Mark
To determine

To calculate:

The maximum revenue and the number of boxes of candy to be sold to maximise the revenue.

Profit function

The maximum profit and the number of boxes of candy the firm has to sell in order to maximise the profit.

The difference between parts (a) and (c) and why is quadratic function a more reasonable model for revenue.

Answer to Problem 80AYU

The maximum revenue is $564.06 and is obtained by selling 119 candy boxes.

P(x) = 0.04 x 2  + 8.25x  250

The maximum profit is $1755.39 and is obtained by selling 103 candy boxes.

The answer is given below.

Explanation of Solution

Given:

The monthly revenue achieved by selling x wrist watches is

R(x) = 9.5x  0.04 x 2

The monthly cost of selling x wrist watches is

C(x) = 1.25x + 250

The profit function is P(x) = R(x)  C(x)

Formula used:

Consider a quadratic function of the form f(x) = a x 2  + bx + c, a  0 .

Then the graph of the above function is a parabola with vertex ( b 2a , f( b 2a ) ) .

This vertex is the highest point if a < 0 and the lowest point if a > 0 .

Therefore, the maximum (or the minimum) value of the function will be f( b 2a ) .

Calculation:

a.We can see that in R(x) = 9.5x  0.04 x 2 , the coefficient of x 2 is 0.04 . Therefore, we have a = 0.04 < 0 .

Thus, the given function is having the maximum value at the vertex.

Thus, we get

b 2a  =  (9.5) 2(0.04)  = 118.75  119 And f( b 2a ) = R(119) = 9.5(119)  0.04 (119) 2  = 564.06

Thus, the vertex is at (119, 564.06) .

Thus, the maximum revenue is $564.06 and is obtained by selling 119 candy boxes.

b. P(x) = R(x)  C(x)

= 9.5x  0.04 x 2   (1.25x + 250)

= 0.04 x 2  + 8.25x  250

Thus, the profit function is P(x) = 0.04 x 2  + 8.25x  250 .

c.We can see that in P(x) = 0.04 x 2  + 8.25x  250 , the coefficient of x 2 is 0.04 . Therefore, we have a = 0.04 < 0 .

Thus, the given function is having the maximum value at the vertex.

Thus, we get

b 2a  =  (8.25) 2(0.04)  = 103.125  103 And f( b 2a ) = P(103) = 0.04 (103) 2  + 8.25(103)  250 = 175.39

Thus, the vertex is at (103, 175.39) .

Thus, the maximum profit is $1755.39 and is obtained by selling 103 candy boxes.

d.The difference between parts (a) and (c) is that part (a) is the revenue function which is the total income that we get after selling the product whereas part (c) is of the profit function which is the gain we made by selling the product, i.e., profit is the gain that we get after subtracting the expenditure form the income.

Revenue is the total income that we get by selling a particular number of the product, that is Revenue = no.products × price/product .

Let the number of products sold be x .

The price per product can be considered as a linear function as the price may increase or decrease with respect to time (or any other variable) and once it starts decreasing then it may not increase any more (in most circumstances).

Thus, let the price be p(x) = a  bx

Therefore, the revenue will be

Revenue = no.products × price/product

= x(a  bx) = ax  b x 2

Thus, the revenue is a quadratic function.

Chapter 3 Solutions

Precalculus

Ch. 3.1 - Prob. 11AYUCh. 3.1 - Prob. 12AYUCh. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 13-20, a linear function is given. a....Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - In Problems 21-28, determine whether the given...Ch. 3.1 - Suppose that f( x )=4x1 and g(x)=2x+5 . a. Solve...Ch. 3.1 - Suppose that f( x )=3x+5 and g(x)=2x+15 . a. Solve...Ch. 3.1 - In parts (a) - (f), use the following figure. a....Ch. 3.1 - In parts (a) - (f), use the following figure. a....Ch. 3.1 - In parts (a) and (b), use the following figure. a....Ch. 3.1 - In parts (a) and (b), use the following figure. a....Ch. 3.1 - In parts (a) and (b), use the following figure. a....Ch. 3.1 - In parts (a) and (b), use the following figure. a....Ch. 3.1 - Prob. 37AYUCh. 3.1 - Prob. 38AYUCh. 3.1 - Prob. 39AYUCh. 3.1 - Prob. 40AYUCh. 3.1 - Prob. 41AYUCh. 3.1 - Prob. 42AYUCh. 3.1 - Prob. 43AYUCh. 3.1 - Prob. 44AYUCh. 3.1 - Prob. 45AYUCh. 3.1 - Prob. 46AYUCh. 3.1 - Prob. 47AYUCh. 3.1 - Prob. 48AYUCh. 3.1 - Prob. 49AYUCh. 3.1 - Prob. 50AYUCh. 3.1 - Prob. 51AYUCh. 3.1 - Prob. 52AYUCh. 3.1 - Which of the following functions might have the...Ch. 3.1 - Which of the following functions might have the...Ch. 3.1 - Under what circumstances is a linear function f( x...Ch. 3.1 - Explain how the graph of f( x )=mx+b can be used...Ch. 3.2 - Plot the points ( 1,5 ),( 2,6 ),( 3,9 ),( 1,12 )...Ch. 3.2 - Find an equation of the line containing the points...Ch. 3.2 - A _____________ is used to help us to see what...Ch. 3.2 - True or False The correlation coefficient is a...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 5-10, examine the scatter diagram and...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - In Problems 11-16, (a) Draw a scatter diagram. (b)...Ch. 3.2 - Candy The following data represent the weight (in...Ch. 3.2 - Tornadoes The following data represent the width...Ch. 3.2 - Video Games and Grade-Point Average Professor...Ch. 3.2 - Prob. 20AYUCh. 3.2 - Prob. 21AYUCh. 3.2 - Prob. 22AYUCh. 3.2 - Prob. 23AYUCh. 3.2 - Prob. 24AYUCh. 3.2 - Prob. 25AYUCh. 3.2 - Prob. 26AYUCh. 3.2 - Prob. 27AYUCh. 3.3 - List the intercepts of the equation y= x 2 9 ....Ch. 3.3 - Prob. 2AYUCh. 3.3 - To complete the square of x 2 5x , you add the...Ch. 3.3 - To graph y= (x4) 2 you shift the graph of y= x 2...Ch. 3.3 - The graph of a quadratic function is called a(n)...Ch. 3.3 - The vertical line passing through the vertex of a...Ch. 3.3 - The x-coordinate of the vertex of f( x )=a x 2...Ch. 3.3 - True or False The graph of f( x )=2 x 2 +3x4 opens...Ch. 3.3 - True or False The y-coordinate of the vertex of f(...Ch. 3.3 - True or False If the discriminant b 2 4ac=0 , the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 13-20, match each graph to one the...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 21-32, graph the function f by...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 33-48, (a) graph each quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 49-54, determine the quadratic...Ch. 3.3 - In Problems 6572, determine, without graphing,...Ch. 3.3 - In Problems 55-62, determine, without graphing,...Ch. 3.3 - In Problems 55-62, determine, without graphing,...Ch. 3.3 - In Problems 55-62, determine, without graphing,...Ch. 3.3 - In Problems, determine, without graphing, whether...Ch. 3.3 - In Problems 55-62, determine, without graphing,...Ch. 3.3 - In Problems, determine, without graphing, whether...Ch. 3.3 - In Problems 55-62, determine, without graphing,...Ch. 3.3 - The graph of the function f( x )=a x 2 +bx+c has...Ch. 3.3 - The graph of the function f(x)=a x 2 +bx+c has...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - In Problems 77-82, for the given functions fandg ,...Ch. 3.3 - Answer Problems 83 and 84 using the following: A...Ch. 3.3 - Answer Problems 83 and 84 using the following: A...Ch. 3.3 - Suppose that f(x)= x 2 +4x21 . (a) What is the...Ch. 3.3 - Suppose that f( x )= x 2 +2x8 . (a) What is the...Ch. 3.3 - Analyzing the Motion of a Projectile A projectile...Ch. 3.3 - Analyzing the Motion of a Projectile A projectile...Ch. 3.3 - Maximizing Revenue Suppose that the manufacturer...Ch. 3.3 - Maximizing Revenue A lawn mower manufacturer has...Ch. 3.3 - Minimizing Marginal Cost The marginal cost of a...Ch. 3.3 - Minimizing Marginal Cost (See Problem 91.) The...Ch. 3.3 - Business The monthly revenue R achieved by selling...Ch. 3.3 - Business The daily revenue R achieved by selling x...Ch. 3.3 - Stopping Distance An accepted relationship between...Ch. 3.3 - Prob. 82AYUCh. 3.3 - Prob. 83AYUCh. 3.3 - Prob. 84AYUCh. 3.3 - Prob. 85AYUCh. 3.3 - Prob. 86AYUCh. 3.3 - Prob. 87AYUCh. 3.3 - Prob. 88AYUCh. 3.3 - Prob. 89AYUCh. 3.3 - Prob. 90AYUCh. 3.3 - Prob. 91AYUCh. 3.3 - Prob. 92AYUCh. 3.4 - Prob. 1AYUCh. 3.4 - Prob. 2AYUCh. 3.4 - Prob. 3AYUCh. 3.4 - Prob. 4AYUCh. 3.4 - Prob. 5AYUCh. 3.4 - Prob. 6AYUCh. 3.4 - Prob. 7AYUCh. 3.4 - Prob. 8AYUCh. 3.4 - Prob. 9AYUCh. 3.4 - Prob. 10AYUCh. 3.4 - Prob. 11AYUCh. 3.4 - Prob. 12AYUCh. 3.4 - Prob. 13AYUCh. 3.4 - Prob. 14AYUCh. 3.4 - Prob. 15AYUCh. 3.4 - Prob. 16AYUCh. 3.4 - Prob. 17AYUCh. 3.4 - Prob. 18AYUCh. 3.4 - Prob. 19AYUCh. 3.4 - Prob. 20AYUCh. 3.4 - Prob. 21AYUCh. 3.4 - Prob. 22AYUCh. 3.4 - Prob. 23AYUCh. 3.4 - Prob. 24AYUCh. 3.4 - Prob. 25AYUCh. 3.4 - Prob. 26AYUCh. 3.4 - Prob. 27AYUCh. 3.4 - Prob. 28AYUCh. 3.4 - Prob. 29AYUCh. 3.4 - Prob. 30AYUCh. 3.4 - Prob. 31AYUCh. 3.5 - Solve the inequality 3x27 .Ch. 3.5 - Write (2,7] using inequality notation.Ch. 3.5 - (a) f( x )0 (b) f( x )0Ch. 3.5 - (a) g( x )0 (b) g( x )0Ch. 3.5 - (a) g( x )f( x ) (b) f( x )g( x )Ch. 3.5 - (a) f( x )g( x ) (b) f( x )g( x )Ch. 3.5 - x 2 3x100Ch. 3.5 - x 2 +3x100Ch. 3.5 - x 2 4x0Ch. 3.5 - x 2 +8x0Ch. 3.5 - x 2 90Ch. 3.5 - x 2 10Ch. 3.5 - x 2 +x12Ch. 3.5 - x 2 +7x12Ch. 3.5 - 2 x 2 5x+3Ch. 3.5 - 6 x 2 6+5xCh. 3.5 - x 2 x+10Ch. 3.5 - x 2 +2x+40Ch. 3.5 - 4 x 2 +96xCh. 3.5 - 25 x 2 +1640xCh. 3.5 - 6( x 2 1 )5xCh. 3.5 - 2( 2 x 2 3x )9Ch. 3.5 - Prob. 23AYUCh. 3.5 - Prob. 24AYUCh. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - In Problems 25-32, use the given functions f and g...Ch. 3.5 - Prob. 33AYUCh. 3.5 - Prob. 34AYUCh. 3.5 - Prob. 35AYUCh. 3.5 - Prob. 36AYUCh. 3.5 - Prob. 37AYUCh. 3.5 - Prob. 38AYUCh. 3.5 - Prob. 39AYUCh. 3.5 - Prob. 40AYUCh. 3.5 - Prob. 41AYUCh. 3.5 - Prob. 42AYUCh. 3.5 - Prob. 43AYUCh. 3 - Prob. 1RECh. 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 - Prob. 13RECh. 3 - Prob. 14RECh. 3 - Prob. 15RECh. 3 - Prob. 16RECh. 3 - Prob. 17RECh. 3 - Prob. 18RECh. 3 - Prob. 19RECh. 3 - Prob. 20RECh. 3 - Prob. 21RECh. 3 - Prob. 22RECh. 3 - Prob. 23RECh. 3 - Prob. 24RECh. 3 - Prob. 25RECh. 3 - Prob. 26RECh. 3 - Prob. 27RECh. 3 - Prob. 28RECh. 3 - Prob. 29RECh. 3 - Prob. 30RECh. 3 - Prob. 31RECh. 3 - Prob. 32RECh. 3 - Prob. 33RECh. 3 - Prob. 34RECh. 3 - Prob. 35RECh. 3 - Prob. 36RECh. 3 - Prob. 37RECh. 3 - Prob. 38RECh. 3 - Prob. 39RECh. 3 - Prob. 40RECh. 3 - Prob. 41RECh. 3 - Prob. 42RECh. 3 - Prob. 43RECh. 3 - Prob. 44RECh. 3 - Prob. 45RECh. 3 - Prob. 46RECh. 3 - Prob. 47RECh. 3 - Prob. 1CTCh. 3 - Prob. 2CTCh. 3 - Prob. 3CTCh. 3 - Prob. 5CTCh. 3 - Prob. 4CTCh. 3 - Prob. 6CTCh. 3 - Prob. 7CTCh. 3 - Prob. 8CTCh. 3 - Prob. 9CTCh. 3 - Find the distance between the points P=( 1,3 ) and...Ch. 3 - Prob. 2CRCh. 3 - Solve the inequality 5x+30 and graph the solution...Ch. 3 - Find the equation of the line containing the...Ch. 3 - Find the equation of the line perpendicular to the...Ch. 3 - Graph the equation x 2 + y 2 4x+8y5=0 .Ch. 3 - Does the following relation represent a function?...Ch. 3 - For the function f defined by f( x )= x 2 4x+1 ,...Ch. 3 - Find the domain of h(z)= 3z1 6z7 .Ch. 3 - Is the following graph the graph of a function?Ch. 3 - Consider the function f(x)= x x+4 . a. Is the...Ch. 3 - Is the function f(x)= x 2 2x+1 even, odd, or...Ch. 3 - Approximate the local maximum values and local...Ch. 3 - If f(x)=3x+5 and g(x)=2x+1 , a. Solve f(x)=g( x )...Ch. 3 - For the graph of the function f , a. Find the...
Knowledge Booster
Background pattern image
Calculus
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, calculus and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Calculus: Early Transcendentals
Calculus
ISBN:9781285741550
Author:James Stewart
Publisher:Cengage Learning
Text book image
Thomas' Calculus (14th Edition)
Calculus
ISBN:9780134438986
Author:Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:PEARSON
Text book image
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:9780134763644
Author:William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:PEARSON
Text book image
Calculus: Early Transcendentals
Calculus
ISBN:9781319050740
Author:Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:W. H. Freeman
Text book image
Precalculus
Calculus
ISBN:9780135189405
Author:Michael Sullivan
Publisher:PEARSON
Text book image
Calculus: Early Transcendental Functions
Calculus
ISBN:9781337552516
Author:Ron Larson, Bruce H. Edwards
Publisher:Cengage Learning
Finding Local Maxima and Minima by Differentiation; Author: Professor Dave Explains;https://www.youtube.com/watch?v=pvLj1s7SOtk;License: Standard YouTube License, CC-BY