Chapter 3: Problem 53
Exer. 53-54: If a linear function \(f\) satisfies the given conditions, find \(f(x)\). $$ f(-3)=1 \text { and } f(3)=2 $$
Short Answer
Expert verified
The function \(f(x) = \frac{1}{6}x + \frac{3}{2}.\)
Step by step solution
01
Identify Two Points
The function passes through the points \[(-3, 1) \text{ and } (3, 2)\].These points are derived from the given condition where function \(f(x)\) gives specific values at specific \(x\)-coordinates: \((-3, 1)\) and \((3, 2)\).
02
Calculate the Slope
The formula for the slope \(m\) of a line is \[\frac{y_2-y_1}{x_2-x_1}.\]Substitute the points \((x_1, y_1) = (-3, 1)\) and \((x_2, y_2) = (3, 2)\) to get the slope:\[m = \frac{2 - 1}{3 - (-3)} = \frac{1}{6}.\]
03
Use Point-Slope Form to Determine Linear Function
With a slope \(m = \frac{1}{6}\) and a point \((-3, 1)\), use the point-slope form of a line which is \[y - y_1 = m(x - x_1).\]Plug in the values:\[y - 1 = \frac{1}{6}(x + 3).\]Distribute and solve for \(y\): \[y - 1 = \frac{1}{6}x + \frac{1}{2},\]\[y = \frac{1}{6}x + \frac{1}{2} + 1,\]\[y = \frac{1}{6}x + \frac{3}{2}.\]Hence, the function is \(f(x) = \frac{1}{6}x + \frac{3}{2}.\)
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.
Point-Slope Form
A linear function can be easily determined using the point-slope form. This form is especially useful when you know the slope of the line and one point it passes through. The general point-slope form equation is \(y - y_1 = m(x - x_1)\), where \((x_1, y_1)\) is a known point on the line and \(m\) is the slope. This equation helps create a specific linear function that describes precisely the line's behavior through the plane.
For example, if you have a slope \(m = \frac{1}{6}\) and a point \((-3, 1)\), placing these into the point-slope form constructs the equation \(y - 1 = \frac{1}{6}(x + 3)\). From this point, it is straightforward to convert it directly into a more familiar linear function format, like slope-intercept form, by simplifying the equation further.
For example, if you have a slope \(m = \frac{1}{6}\) and a point \((-3, 1)\), placing these into the point-slope form constructs the equation \(y - 1 = \frac{1}{6}(x + 3)\). From this point, it is straightforward to convert it directly into a more familiar linear function format, like slope-intercept form, by simplifying the equation further.
Slope Calculation
The slope of a line is fundamental in understanding how the line moves through the coordinate plane. It measures how much the line rises (or falls) for a given run, and is sometimes described as the "steepness" of the line. The formula for determining slope \(m\) between two points \((x_1, y_1)\) and \((x_2, y_2)\) is \(\frac{y_2-y_1}{x_2-x_1}\).
In our exercise, using the points \((-3, 1)\) and \((3, 2)\), this becomes \( \frac{2-1}{3 - (-3)} = \frac{1}{6} \). This means that for every 6 units you move horizontally, the line moves 1 unit vertically. Understanding slope helps predict how changing \(x\) impacts \(y\), which is critical in graphical and algebraic problem-solving.
In our exercise, using the points \((-3, 1)\) and \((3, 2)\), this becomes \( \frac{2-1}{3 - (-3)} = \frac{1}{6} \). This means that for every 6 units you move horizontally, the line moves 1 unit vertically. Understanding slope helps predict how changing \(x\) impacts \(y\), which is critical in graphical and algebraic problem-solving.
Function Notation
Function notation is a way to express equations that denote a relationship between variables. It uses symbols like \( f(x) \) to specify that \( y \) is a function of \( x \), emphasizing the dependence of one variable on another. In our context, the result of finding the function that meets the given conditions can be written as \( f(x) = \frac{1}{6}x + \frac{3}{2} \).
This notation provides scale-invariant communication, making it easier to represent calculations without confusion. It's particularly helpful when introducing multiple functions, as each can have a clear, specific notation, such as \( f(x), g(x), \) or \( h(x) \). The function notation also assists in illustrating the output for each input \( x \). This enables deeper insights into mathematical analysis and inquiry.
This notation provides scale-invariant communication, making it easier to represent calculations without confusion. It's particularly helpful when introducing multiple functions, as each can have a clear, specific notation, such as \( f(x), g(x), \) or \( h(x) \). The function notation also assists in illustrating the output for each input \( x \). This enables deeper insights into mathematical analysis and inquiry.
Linear Equations
A linear equation is any equation that forms a straight line when graphed. They are represented in the form \(ax + by = c\) or \(y = mx + b\), where \(m\) is the slope and \(b\) is the y-intercept. Linear equations define a consistent, predictable relationship between two variables.
In the case of the given problem, we derived the equation \(y = \frac{1}{6}x + \frac{3}{2}\). Here, \(\frac{1}{6}\) is the slope, and \(\frac{3}{2}\) is the y-intercept, indicating the basic form of our linear relationship.
Understanding linear equations is crucial as they form the backbone of more complex mathematical concepts and are widely applied in real-world scenarios, from calculating budgets to analyzing scientific data.
In the case of the given problem, we derived the equation \(y = \frac{1}{6}x + \frac{3}{2}\). Here, \(\frac{1}{6}\) is the slope, and \(\frac{3}{2}\) is the y-intercept, indicating the basic form of our linear relationship.
Understanding linear equations is crucial as they form the backbone of more complex mathematical concepts and are widely applied in real-world scenarios, from calculating budgets to analyzing scientific data.