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Ch. 3 - Derivatives
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Not the one you use?Change textbook
Chapter 3, Problem 30b

Consider the following cost functions.
b. Determine the average cost and the marginal cost when x=a.
C(x) = 500+0.02x, 0≤x≤2000, a=1000

Verified step by step guidance
1
To find the average cost, we need to divide the total cost function C(x) by the number of units x. The average cost function A(x) is given by A(x) = C(x) / x.
Substitute the given cost function C(x) = 500 + 0.02x into the average cost formula: A(x) = (500 + 0.02x) / x.
Simplify the expression for A(x): A(x) = 500/x + 0.02.
To find the average cost at x = a, substitute a = 1000 into the average cost function: A(1000) = 500/1000 + 0.02.
The marginal cost is the derivative of the cost function C(x) with respect to x. Differentiate C(x) = 500 + 0.02x to find C'(x), which is the marginal cost. Since C(x) is linear, C'(x) = 0.02. The marginal cost at x = a is simply C'(1000) = 0.02.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Cost Functions

A cost function represents the total cost incurred by a firm in producing a certain quantity of goods, denoted as C(x). In this case, C(x) = 500 + 0.02x indicates that there is a fixed cost of 500 and a variable cost that increases linearly with the quantity produced (x). Understanding the structure of cost functions is essential for analyzing production costs.
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Average Cost

The average cost is calculated by dividing the total cost by the quantity produced, expressed as AC(x) = C(x)/x. It provides insight into the cost per unit of production. For the given cost function, calculating the average cost at x = a (where a = 1000) will help determine how efficiently resources are being utilized at that production level.
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Marginal Cost

Marginal cost refers to the additional cost incurred by producing one more unit of a good, mathematically represented as MC(x) = C'(x). It is derived from the derivative of the cost function. For the provided cost function, finding the marginal cost at x = a (x = 1000) will indicate how production costs change with incremental increases in output, which is crucial for decision-making in production.
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