Chapter 6: Problem 20
A linear function is given. Evaluate the function at the indicated values and then graph the function over its given domain. $$f(x)=-2+1.7 x, x=2,3,4,5,6,7 ; f(2), f(7)$$
Short Answer
Expert verified
\( f(2) = 1.4 \), \( f(7) = 9.9 \); graph is a line with given points.
Step by step solution
01
Understand the Function
The given function is linear and expressed as \( f(x) = -2 + 1.7x \). This means it's a straight line on the graph. You need to evaluate this function at certain values of x: 2, 3, 4, 5, 6, and 7. You'll also specifically find \( f(2) \) and \( f(7) \).
02
Evaluate the Function at x = 2
To find \( f(2) \), substitute 2 for x in the function: \( f(2) = -2 + 1.7 \times 2 \). Calculating this gives \( f(2) = -2 + 3.4 = 1.4 \).
03
Evaluate the Function at x = 3
Substitute 3 for x in the function: \( f(3) = -2 + 1.7 \times 3 \). Calculating this gives \( f(3) = -2 + 5.1 = 3.1 \).
04
Evaluate the Function at x = 4
Substitute 4 for x in the function: \( f(4) = -2 + 1.7 \times 4 \). Calculating this gives \( f(4) = -2 + 6.8 = 4.8 \).
05
Evaluate the Function at x = 5
Substitute 5 for x in the function: \( f(5) = -2 + 1.7 \times 5 \). Calculating this gives \( f(5) = -2 + 8.5 = 6.5 \).
06
Evaluate the Function at x = 6
Substitute 6 for x in the function: \( f(6) = -2 + 1.7 \times 6 \). Calculating this gives \( f(6) = -2 + 10.2 = 8.2 \).
07
Evaluate the Function at x = 7
Substitute 7 for x in the function: \( f(7) = -2 + 1.7 \times 7 \). Calculating this gives \( f(7) = -2 + 11.9 = 9.9 \).
08
Plot the Points and Graph the Function
Now that you have the points (2, 1.4), (3, 3.1), (4, 4.8), (5, 6.5), (6, 8.2), and (7, 9.9), plot these on a graph. The straight line passing through these points is the graph of the linear function \( f(x) = -2 + 1.7x \).
09
Conclusion
The evaluated function values are \( f(2) = 1.4 \) and \( f(7) = 9.9 \). These, along with other evaluated points, help in plotting the graph of the function over the domain \( x = 2 \) to \( x = 7 \).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Function Evaluation
Evaluating a function involves substituting a specific value for the variable, usually denoted as \( x \), in the function equation. In this case, the function is \( f(x) = -2 + 1.7x \), which is a linear function. To evaluate \( f(x) \) at a particular value, substitute the given \( x \) value into the function and perform the necessary arithmetic operations.
Here's how we can evaluate some values:
Here's how we can evaluate some values:
- For \( x = 2 \), substitute 2 into the equation: \( f(2) = -2 + 1.7 \times 2 = 1.4 \).
- For \( x = 3 \), use the function: \( f(3) = -2 + 1.7 \times 3 = 3.1 \).
- Similarly, evaluate for other values: \( f(4), f(5), f(6), \) and \( f(7) \).
Graphing Functions
Once you have evaluated several points, you can plot them on a graph to visualize the function. Graphing a linear function like \( f(x) = -2 + 1.7x \) is straightforward since it will form a straight line. You only need two points to draw a line, but having more verifies that the calculations are accurate and that the graph truly represents the function.
Here are the typical steps for graphing:
Here are the typical steps for graphing:
- Plot each point on the graph, such as (2, 1.4), (3, 3.1), and so on.
- Draw a line through these plotted points. With linear functions, this line should extend endlessly in both directions.
- Make sure the line passes through all your calculated points; any deviations might indicate calculation errors.
Domain of a Function
The domain of a function refers to all the possible input values (\( x \)-values) for which the function is defined. For linear functions such as \( f(x) = -2 + 1.7x \), the domain is typically all real numbers unless specified otherwise. In our exercise, the domain is specifically provided, ranging from \( x = 2 \) to \( x = 7 \).
Understanding the domain is essential because:
Understanding the domain is essential because:
- It helps you know where to evaluate the function.
- Restricting or defining a domain can sometimes change the appearance of a graph, such as turning a line into a line segment.
- Ensures that when you graph the function, you only include the relevant part of the graph. This keeps your graph accurate and allows you to focus on the given problem.