GED Mathematical Reasoning TestAlgebraic Problem Solving with Graphs and FunctionsEasy

A production manager is analyzing the cost of manufacturing a new product. The cost, C, in dollars, is a function of the number of units produced, x, and is given by the equation C(x) = 5x + 150. What is the practical domain of this function if the company can produce a minimum of 0 units and a maximum of 100 units?

  1. Ax ≥ 0
  2. B[150, 650]
  3. C(-∞, ∞)
  4. D[0, 100]
Show answer & explanation

Correct answer: D. [0, 100]

The practical domain represents the realistic input values for the number of units produced. Since the company can produce between 0 and 100 units, inclusive, the domain is the closed interval [0, 100].

Why the other options are wrong

  • A. This represents all non-negative numbers, but does not include the upper limit of 100 units.
  • B. This represents the practical range of the cost, not the domain (number of units).
  • C. This represents all real numbers, which is not practical for units produced.

Practical Domain

The practical domain of a function represents the set of all realistic input values that make sense within the context of a real-world problem.

  • Considers physical or practical limitations.
  • Often restricted to non-negative numbers or specific ranges.
  • Different from the mathematical domain, which includes all values for which the function is defined.

Memory trick: Real-world limits define the input road.

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