Chapter 8: Problem 32
Find an equation of the line passing through the given points. Use function notation to write the equation. $$ (-9,-2),(-3,10) $$
Short Answer
Expert verified
The equation of the line is \(f(x) = 2x + 16\).
Step by step solution
01
Identify the Slope Formula
The first step is to use the formula for the slope of a line connecting two points \((x_1, y_1)\) and \((x_2, y_2)\), which is given by \(m = \frac{y_2 - y_1}{x_2 - x_1}\).
02
Substitute Points into the Slope Formula
Substitute the given points \((-9, -2)\) and \((-3, 10)\) into the slope formula: \[ m = \frac{10 - (-2)}{-3 - (-9)} = \frac{12}{6} = 2 \]. Thus, the slope \(m\) of the line is 2.
03
Write the Point-Slope Form Equation
The point-slope form of a line is \(y - y_1 = m(x - x_1)\). Substitute the slope \(m = 2\) and one of the points, say \((-9, -2)\), into this equation: \[ y - (-2) = 2(x - (-9)) \].
04
Simplify the Equation to Function Notation
Simplify the equation from the previous step: \(y + 2 = 2(x + 9)\). Distribute and simplify to get \(y + 2 = 2x + 18\), then subtract 2 from both sides to get the function \(y = 2x + 16\).
05
Write the Final Equation in Function Notation
The equation of the line in function notation is \(f(x) = 2x + 16\), representing the line passing through the given points.
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 Formula
The slope formula is a key tool in understanding linear equations. It is used to determine the steepness or incline of a line by calculating the ratio of the vertical change (rise) to the horizontal change (run) between two points. This is expressed mathematically as \(m = \frac{y_2 - y_1}{x_2 - x_1}\). For the points given in our exercise, \((-9, -2)\) and \((-3, 10)\), the slope \(m\) is found by:
- Subtracting the \(y\) values: \(10 - (-2) = 12\).
- Subtracting the \(x\) values: \(-3 - (-9) = 6\).
- Dividing the differences: \(m = \frac{12}{6} = 2\).
Point-Slope Form
Once the slope is known, the point-slope form of a linear equation comes into play. This is a convenient form for writing the equation of a line when a point on the line and the slope are known. The point-slope form is expressed as \(y - y_1 = m(x - x_1)\). With the slope \(m = 2\) and the point \((-9, -2)\), we substitute into the equation:
- The equation becomes \(y - (-2) = 2(x - (-9))\).
- This simplifies to \(y + 2 = 2(x + 9)\).
Function Notation
Function notation is a way of expressing the relationship between \(x\) and \(y\), where \(y\) is a function of \(x\). In mathematical terms, this is written as \(f(x)\). Once you've simplified the point-slope expression, you can rewrite it in function notation. Our earlier point-slope form \(y + 2 = 2(x + 9)\) simplifies further to:
- Distribute \(2\) to both terms: \(y + 2 = 2x + 18\).
- Isolate \(y\) by subtracting 2: \(y = 2x + 16\).
Algebraic Methods
Algebraic methods are the systematic procedures used to find the solutions in math problems like ours. Here's a step-by-step recap using algebraic methods when dealing with linear equations:
- First, calculate the slope using the slope formula: \(m = \frac{y_2 - y_1}{x_2 - x_1}\).
- Next, apply the point-slope form: \(y - y_1 = m(x - x_1)\).
- Simplify the equation, making it easier to interpret and use.
- Use algebraic manipulation to express the equation in function notation: \(f(x) = mx + b\).