PARALLEL AND PERPENDICULAR LINES SECTION 4 4 AGENDA
- Slides: 11
PARALLEL AND PERPENDICULAR LINES SECTION 4. 4
AGENDA • Warm-Up • Parallel vs. Perpendicular Lines Class Investigation • Can we discover the main idea on our own? Let’s Check!! • Power. Point/Notes
PARALLEL LINES • When are 2 lines parallel? e h t e v a h y ! e e h t p o l n s e Wh same
Example 1 Watch Me! Write the slope-intercept form of an equation for the line that passes through (4, – 2) and is parallel to the graph of Steps: • Identify the slope. • Think about the slope of the new line (how can we adjust it to be parallel or perpendicular? ). • Use the slope and a point to write an equation of the line!
Example 1 You Try!!! Write the slope-intercept form of an equation for the line that passes through (2, 3) and is parallel to the graph of A. B. C. D.
PERPENDICULAR LINES • When are 2 lines perpendicular? e ! v e a h slop y e l h t a c n o e r Wh -recip e t i s o p p o
Example 2 Parallel vs. Perpendicular (Watch!) Determine whether the following lines are parallel or perpendicular! Remember: Start by rewriting each equation in slope-intercept form!
Example 2 You Try!!! Determine whether the following lines are parallel or perpendicular! A. y = – 2 x + 1 and x – 2 y = – 4 are perpendicular. None of the lines are parallel. B. y = – 2 x + 1 and y = 3 are perpendicular. None of the lines are parallel. C. y = – 2 x + 1 and x – 2 y = – 4 are parallel. None of the lines are perpendicular. D. None of the lines are parallel or perpendicular.
Example 3 Watch Me! Write an equation in slope-intercept form for the line that passes through (4, – 1) and is perpendicular to the graph of 7 x – 2 y = 3. Steps: • Identify the slope. • Think about the slope of the new line (how can we adjust it to be parallel or perpendicular? ). • Use the slope and a point to write an equation of the line!
Example 3 You Try!!! Write an equation in slope-intercept form for the line that passes through (– 3, – 2) and is perpendicular to the graph of x + 4 y = 12. A. B. C. D.
Homework: On the back of your notes sheet!