Lesson 14 Linear Equations Calculating Slope From Graphs

Lesson 14 Linear Equations Calculating Slope From Graphs

Warm-Up Write each fraction in simplest form. Do not convert to mixed numbers. 1. 2. 3. 4. 5.

Calculating Slope From Graphs Target: Use slope triangles to find the slope of lines.

Vocabulary � Slope: The ratio of the vertical change to the horizontal change in a linear graph. � Slope Triangle: A right triangle where one leg of the triangle represents the vertical rise and the other leg is the horizontal run in a linear graph.

Finding Slope The slope of a line is the ratio of the change in y-values to the change in x-values.

Example 1 a Draw a slope triangle for the line and identify the slope of the line. -1 +2

Example 1 b Draw a slope triangle for the line and identify the slope of the line. +2 +2

Example 1 c Draw a slope triangle for the line and identify the slope of the line. +3

Example 1 d Draw a slope triangle for the line and identify the slope of the line. +3

Example 2 a Graph the line that goes through the given points, draw a slope triangle and give the slope. -6 +3

Example 2 b Graph the line that goes through the given points, draw a slope triangle and give the slope. (0, 1) and (2, 4) +2 +3

Example 3 Graph a line with a slope of 2. � Write slope as a fraction. +1 � Pick a y-intercept. � Rise +2, Run +1 � Draw the line. +2

Exit Problems Is the slope of each line positive, negative, zero or undefined?

Communication Prompt How do you find the slope of a line from a graph?