Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
4. Polynomial Functions
Quadratic Functions
Problem 7e
Textbook Question
Solve each problem. During the course of ayear, the number of volunteers available to run a food bank each month is modeled by V(x), where V(x)=2x^2-32x+150 between the months of January and August. Here x is time in months, with x=1 representing January. From August to December, V(x) is mod-eled by V(x)=31x-226. Find the number of volunteers in each of the following months. December
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1
Identify the function that models the number of volunteers from August to December: \( V(x) = 31x - 226 \).
Determine the value of \( x \) for December. Since \( x = 1 \) represents January, \( x = 12 \) represents December.
Substitute \( x = 12 \) into the function \( V(x) = 31x - 226 \).
Calculate \( 31 \times 12 \) to find the first part of the expression.
Subtract 226 from the result of \( 31 \times 12 \) to find the number of volunteers in December.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Quadratic Functions
A quadratic function is a polynomial function of degree two, typically expressed in the form V(x) = ax^2 + bx + c. In this case, V(x) = 2x^2 - 32x + 150 models the number of volunteers from January to August. Understanding how to evaluate quadratic functions is essential for determining the number of volunteers during these months.
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Linear Functions
A linear function is a polynomial function of degree one, represented as V(x) = mx + b, where m is the slope and b is the y-intercept. For the months from August to December, the number of volunteers is modeled by V(x) = 31x - 226. Recognizing how to work with linear functions is crucial for calculating the number of volunteers in the later months.
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Linear Inequalities
Function Evaluation
Function evaluation involves substituting a specific value of x into a function to find the corresponding output. To find the number of volunteers in December, one must evaluate the appropriate function for that month. Since December corresponds to x = 12, understanding how to correctly substitute and compute the value is key to solving the problem.
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