Chapter 10: Problem 55
Sketch the graph of each polynomial function. First graph the function on a calculator and use the calculator graph as a guide. $$f(x)=x-20$$
Short Answer
Expert verified
Plot points (0, -20) and (20, 0), then draw a straight line through them.
Step by step solution
01
Identify the Function
The given function is a linear polynomial function: \[f(x) = x - 20\]
02
Determine Key Points
For a linear function, the key points are the y-intercept and some additional points. Here, the y-intercept is found by setting \(x = 0\), which gives:\[f(0) = 0 - 20 = -20\]Another simple point can be found by setting \(x = 20\):\[f(20) = 20 - 20 = 0\]
03
Plot the Points
Plot the two key points on the graph. They are (0, -20) and (20, 0).
04
Draw the Line
Using the two points, draw a straight line through them. This line represents the graph of the function \(f(x) = x - 20\).
05
Verify with Calculator
Graph the function using a graphing calculator to ensure accuracy. The calculator should show a straight line passing through the points (0, -20) and (20, 0). Use this as a guide to adjust your sketch if necessary.
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.
linear polynomial
A linear polynomial is one of the simplest forms of polynomials. It is a polynomial of degree one. This means it has the form \[f(x) = ax + b\] where \(a\) and \(b\) are constants and \(x\) is the variable.
For our specific example, \[f(x) = x - 20\] we see that \(a = 1\) and \(b = -20\). Since the highest exponent of \(x\) is 1, this is called a linear function.
Linear functions graph as straight lines. They are easy to work with, which makes them a great starting point when studying polynomials.
For our specific example, \[f(x) = x - 20\] we see that \(a = 1\) and \(b = -20\). Since the highest exponent of \(x\) is 1, this is called a linear function.
Linear functions graph as straight lines. They are easy to work with, which makes them a great starting point when studying polynomials.
y-intercept
The y-intercept is a very important part of any graph. It is where the graph crosses the y-axis. To find the y-intercept, you set \(x\) to 0 and solve for \(y\).
In our function, \[f(x) = x - 20\], we set \(x = 0\).
So, \[f(0) = 0 - 20 = -20\].
That means the y-intercept is at the point (0, -20). This point is crucial as it gives you one of the reference points you need to draw the graph.
When plotting, always start with the y-intercept. Since it is easy to find, it gives you a strong footing for sketching the graph accurately.
In our function, \[f(x) = x - 20\], we set \(x = 0\).
So, \[f(0) = 0 - 20 = -20\].
That means the y-intercept is at the point (0, -20). This point is crucial as it gives you one of the reference points you need to draw the graph.
When plotting, always start with the y-intercept. Since it is easy to find, it gives you a strong footing for sketching the graph accurately.
plotting points
Plotting points correctly is essential when graphing any function. For linear functions, you need at least two points to draw a straight line.
In the provided example, we found two key points: (0, -20) and (20, 0).
Here are the steps to plot these points:
In the provided example, we found two key points: (0, -20) and (20, 0).
Here are the steps to plot these points:
- First, place a dot at (0, -20) on your graph. This is the y-intercept.
- Next, place another dot at (20, 0). This is another critical point.
graphing calculator
A graphing calculator is an invaluable tool when studying polynomial functions. It helps you visualize the function and verify your calculations.
Here’s how you can use a graphing calculator to graph a function like \[f(x) = x - 20\]:
Here’s how you can use a graphing calculator to graph a function like \[f(x) = x - 20\]:
- First, turn on the calculator and enter the function into the ‘y=’ menu.
- Next, press the ‘Graph’ button. The calculator will then display the graph of the function on the screen.
- To zoom in or out, use the zoom buttons to see the graph more clearly.
- Use the computed graph to verify the accuracy of your hand-drawn graph.