1. Chapter 6: Slope and Lines Lesson 6-4: Slope-Intercept Equations for Lines Mrs. Parziale

2. Vocabulary: The y-intercept is the point (0,b) where the graph intersects with the y-axis at b. Slope-intercept form – an equation of a line written as

3. Slope-Intercept Property: The line with equation y = mx + b has slope ____ and y-intercept ______. Example 1: Give the slope and the y- intercept: a) m b

4. Example 1, cont. Give the slope and the y-intercept of the following equations: b) m = ______ y-int = _____ c) m = ______ y-int = _____

5. Graph the lines on the grid.

6. Example 2: Write the following equation in slope- intercept form. Give the slope and y-intercept.

7. Example 3: Write an equation for the line with slope 5 and y-intercept of -1. Graph the line.

8. Example 4: Find an equation of the line graphed below.

9. Example 5 Assume that a skydiver opens a parachute and falls at a speed of 10 ft per second from 5000 ft above the ground. a)Find an equation in slope-intercept form for the height h of the skydiver after x seconds. a)How high is the skydiver after 5 minutes (300 seconds)?

10. Direct Variation A special case of a linear equation occurs when the y- intercept is at the __________. The y-intercept is _____ and y = mx + b becomes __________. This means that y is a _____________________ of x. origin (0,0) y = mx constant multiple

11. Closure What is the y-intercept? –Where do you find it on a graph? –Where do you find it in an equation? What is the slope-intercept form of an equation? –Using the equation how do you find slope? –Using the equation how do you find the y- intercept?