1. Parallel and Perpendicular Equations

2. Definitions Parallel Lines- have the same slope. –Since they rise and run at the same levels. –Cross the y-axis at different points though. Perpendicular Lines- cross at 90° –They make an exact corner. –You have to “flip-op” the slope of a perpendicular line to get the new equation.

3. Steps… Parallel 1.Copy the slope of the equation given. 2.Using the point-slope form, plug in the ordered pair and the slope to find the equation. Perpendicular 1.“ flip-op” the slope in the equation given. 2.Using the point-slope form, plug in the “flip- op” slope and the ordered pair to find the equation.

4. Example 6-1a Write the slope-intercept form of an equation for the line that passes through (4, –2) and is parallel to the graph of Answer:The equation is

5. Example 6-1d CheckYou can check your result by graphing both equations. The lines appear to be parallel. The graph of passes through (4, –2).

6. Example 6-1e Write the slope-intercept form of an equation for the line that passes through (2, 3) and is parallel to the graph of Answer:

7. Example 6-2a Geometry The height of a trapezoid is measured on a segment that is perpendicular to a base. In trapezoid ARTP, and are bases. Can be used to measure the height of the trapezoid? Explain.

8. Example 6-3a Write the slope-intercept form for an equation of a line that passes through (4, –1) and is perpendicular to the graph of Answer: The equation of the line is

9. Example 5 Write the slope-intercept form for an equation of a line that passes through (–3, 6) and is perpendicular to the graph of Answer:

10. Example 6 Write the slope-intercept form for an equation of a line perpendicular to the graph of and passes through (0, 6). Answer: The equation of the line is

11. Example 7 Write the slope-intercept form for an equation of a line perpendicular to the graph of and passes through the x -intercept of that line. Answer: