Chapter 4: Problem 89
For the following exercises, which of the tables could represent a linear function? For each that could be linear, find a linear equation that models the data. $$ \begin{array}{|c|c|c|c|c|} \hline \boldsymbol{x} & 0 & 5 & 10 & 15 \\ \hline \boldsymbol{g}(\boldsymbol{x}) & 5 & -10 & -25 & -40 \\ \hline \end{array} $$
Short Answer
Step by step solution
Understanding a Linear Function
Calculate the Difference in x-values
Calculate the Difference in g(x)-values
Determine the Slope
Find the y-intercept
Write the Linear Equation
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.
Slope Calculation
To calculate the slope, you divide the difference in the \( y \)-values by the difference in the \( x \)-values. For instance, if the values change from \(-10\) to \(5\), the slope \( m \) would be calculated as:
- Calculate the difference in \( g(x) \)-values: \(-10 - 5 = -15\)
- Calculate the difference in \( x \)-values: \(5 - 0 = 5\)
- Finally, compute the slope: \( m = \frac{-15}{5} = -3 \)
Linear Equation
Understanding the linear equation involves knowing three key parts:
- The slope \( m \), which determines the tilt of the line
- The \( x \) variable, which represents the independent variable
- The \( b \) or y-intercept, showing where the line crosses the y-axis
Rate of Change
An increasing function has a positive rate of change, and the line tilts upwards. Conversely, a negative rate of change means the function decreases, tilting downwards.
In our example, the rate of change is \(-3\). For every increase of 1 in \( x \), \( g(x) \) decreases by 3. This showcases a constant downward trend.
Y-Intercept
To find the y-intercept in our equation, recognize when \( x = 0 \). In the equation \( g(x) = -3x + 5 \), setting \( x \) to zero leaves us with \( g(0) = 5 \). Thus, the y-intercept is 5.
This means that no matter what the slope is, the graph will always start from this point on the y-axis. Visually, it sets the initial height of the line on a graph.