In Exercises 5–6, use the function's equation, and not its graph, to find (a) the minimum or maximum value and where it occurs. (b) the function's domain and its range.
Table of contents
- 0. Review of Algebra4h 18m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations1h 43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 5m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 22m
- 10. Combinatorics & Probability1h 45m
4. Polynomial Functions
Quadratic Functions
Problem 7d
Textbook Question
Solve each problem. During the course of a year, the number of volunteers available to run a food bank each month is modeled by , where between the months of January and August. Here x is time in months, with x=1 representing January. From August to December, is modeled by . Find the number of volunteers in each of the following months.
October
Verified step by step guidance1
Identify which piece of the piecewise function applies to October. Since October is the 10th month, and the function V(x) = 31x - 226 applies from August (x=8) to December (x=12), use this formula for x = 10.
Substitute x = 10 into the function V(x) = 31x - 226 to set up the expression for the number of volunteers in October.
Write the expression as V(10) = 31 \times 10 - 226.
Simplify the multiplication part first: calculate 31 \times 10.
Subtract 226 from the result of the multiplication to find the number of volunteers in October.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
3mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Piecewise Functions
A piecewise function is defined by different expressions depending on the input value's domain. In this problem, V(x) uses one formula from January to August and another from August to December, so understanding how to apply the correct formula based on the month is essential.
Recommended video:
Function Composition
Substitution in Functions
Substitution involves replacing the variable in a function with a specific value to find the output. Here, to find the number of volunteers in October, substitute x = 10 into the appropriate piece of the function.
Recommended video:
Guided course
Solving Systems of Equations - Substitution
Linear and Quadratic Functions
The problem involves both quadratic (2x² - 32x + 150) and linear (31x - 226) functions. Recognizing the type of function helps in understanding the shape and behavior of the volunteer count over time and correctly evaluating the expressions.
Recommended video:
Introduction to Quadratic Equations
Watch next
Master Properties of Parabolas with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice
Textbook Question
682
views
