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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 3, Problem 59

Graph the line passing through the given point and having the indicated slope. Plot two points on the line. through (3, -4), m = - 1/3

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Identify the given point and slope. The point is (3, -4) and the slope is \( m = -\frac{1}{3} \).
Use the point-slope form of the equation of a line: \( y - y_1 = m(x - x_1) \), where \( (x_1, y_1) \) is the given point.
Substitute the given point and slope into the point-slope form: \( y - (-4) = -\frac{1}{3}(x - 3) \). Simplify this to get \( y + 4 = -\frac{1}{3}(x - 3) \).
Find the y-coordinate of a second point by choosing a value for \( x \) different from 3, substitute it into the equation, and solve for \( y \). This gives you a second point on the line.
Use the slope \( m = -\frac{1}{3} \) to find a third point by moving 3 units horizontally and 1 unit vertically from the original point, following the slope direction. Plot the original point and these two points, then draw the line through them.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Slope of a Line

The slope represents the rate of change or steepness of a line, calculated as the ratio of the vertical change to the horizontal change between two points. A slope of -1/3 means the line falls 1 unit vertically for every 3 units it moves horizontally to the right.
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The Slope of a Line

Point-Slope Form of a Line

The point-slope form, y - y₁ = m(x - x₁), is used to write the equation of a line when a point (x₁, y₁) and slope m are known. It helps in finding other points on the line by substituting values for x or y.
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Point-Slope Form

Plotting Points on a Coordinate Plane

Plotting points involves marking specific (x, y) coordinates on the Cartesian plane. To graph a line, you plot the given point and use the slope to find a second point by moving horizontally and vertically according to the slope.
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Graphs & the Rectangular Coordinate System