Chapter 1: Problem 22
Graph the function by hand. $$f(x)=\left\\{\begin{array}{ll} 3, & x \leq-1 \\ -x+2, & x>-1 \end{array}\right.$$
Short Answer
Expert verified
The graph of the given piecewise function consists of a horizontal line at \(y = 3\) for \(x \leq -1\), and the line \(y = -x + 2\) for \(x > -1\).
Step by step solution
01
Understanding the Piecewise Definition
This function is defined differently on different intervals. For \(x \leq -1\), \(f(x) = 3\). This is a constant function that will plot as a horizontal line at \(y = 3\). For \(x > -1\), \(f(x) = -x+2\). This is a linear function having a slope of -1 and y-intercept of 2.
02
Graphing \(f(x) = 3\) on the interval \(x \leq -1\)
Start by plotting the constant function \(f(x) = 3\) for \(x \leq -1\). Draw a horizontal line at \(y = 3\) starting from \(x = -1\) and extend it to the left. Include a filled circle at \((-1, 3)\) to indicate that the value at \(x = -1\) is included in this piece.
03
Graphing \(f(x) = -x+2\) on the interval \(x > -1\)
Next, plot the linear function \(f(x) = -x+2\) for \(x > -1\). Use the y-intercept, which is \(2\), and the negative slope to draw the line. Start by placing an open circle at the point \((-1, 3)\) because the value at \(x = -1\) is not included in this part of the function. Then, since the slope is -1, for every 1 unit move to the right, move 1 unit down, and draw the line.
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.
Graphing Piecewise Functions
Graphing piecewise functions involves understanding how to plot separate sections of a function that are defined by different rules over different intervals of the input variable, usually denoted as "x." In the given piecewise function:
- For values of \(x \leq -1\), the function is constant, \(f(x) = 3\).
- For values of \(x > -1\), the function is \(f(x) = -x + 2\).
- Identify intervals and corresponding functions for each region.
- Plot each section individually, maintaining consistent conditions for boundaries like open or closed circles to show included or excluded values.
- Visualize transitioning from one piece to the other smoothly, respecting these boundaries.
Constant Function
A constant function is a type of function where the output value does not change regardless of the input value. It is represented by a single horizontal line on a graph.For our function, on the interval \(x \leq -1\), the function value is always \(f(x) = 3\), creating a constant horizontal line at \(y = 3\). This reflects the idea that for any input within this range, the output is a fixed number.
The distinguishing characteristics of a constant function are:
The distinguishing characteristics of a constant function are:
- It appears visually as a horizontal line in its defined region.
- There are no slopes in a constant function, as the rate of change (or gradient) is zero across the interval.
- Constant functions do not depend on \(x\), other than defining where the line exists on the graph.
Linear Function
Linear functions are identified by their straight-line graphs, and they have an equation of the form \(y = mx + c\), where \(m\) is the slope and \(c\) is the y-intercept. In the interval \(x > -1\), the function we are concerned with is \(f(x) = -x + 2\).For plotting, focus on:
- Y-intercept: This is at \(y = 2\) when \(x = 0\).
- Slope: The slope \(m = -1\) means for every increase in \(x\), \(y\) decreases by \(1\). This shows how steeply the line declines.
Slope-Intercept Form
The slope-intercept form of a linear function is commonly written as \(y = mx + c\), where \(m\) represents the slope of the line, and \(c\) is the y-intercept, the location where the line crosses the y-axis. Understanding how this form shapes the graph is critical. Here's what you need to remember:
- The slope \(m\) determines the line's inclination. A positive slope moves the line upwards as you move right, while a negative slope, like \(-1\) in \(-x + 2\), moves it downward.
- The y-intercept \(c\) pinpoints the starting point on the y-axis. For instance, \(c = 2\) suggests the line crosses the y-axis at \(y = 2\).