Presentation on theme: "Day Problems Graph each equation."— Presentation transcript:
1 Day Problems Graph each equation. 1. y – 2 = (x – 3) 2. y + 3 = -2(x – 1)Write an equation in point-slope form for the line through the given point with the given slope.3. (4 , 2); m = (-5 , 2); m = 0A line passes through the given points. Write an equation for the line in point-slope form. Then rewrite the equation in slope-intercept form.5. (-1 , 0) , (1 , 2)
2 6.5 Parallel and Perpendicular Lines 2/22/11 Parallel lines – lines in the same plane that never intersect.
3 Slopes of Parallel Lines Nonvertical lines are parallel if they have the SAME SLOPE and DIFFERENT Y-INTERCEPTS. Any two vertical lines are parallel.Example – The equations y = 2x + 1 and y = 2x + 3 have the same slope, 2, and different y-intercepts. The graphs of the two equations are parallel.
4 Determining Whether Lines are Parallel Are the graphs of and 2x + 6y = 12 parallel? Explain.Write 2x + 6y = 12 in slope-intercept form. Then compare withThe lines are parallel. The equations have the same slope, , and different y-intercepts.
5 Writing Equations of Parallel Lines Write an equation for the line that contains (5 , 1) and is parallel toStep 1 – Identify the slope of the given line.Step 2 – Write an equation of the line through (5 , 1) using point-slope form, then change to slope-intercept.
6 Perpendicular Lines 2/23/11 Perpendicular lines – lines that intersect to form right angles.SLOPES OF PERPENDICULAR LINESTwo lines are perpendicular their slope is the opposite reciprocal of the given slope. A vertical and horizontal line are also perpendicular.EXAMPLE – the slope of is The slope of y = 4x + 2 is 4.
7 Opposite Reciprocal How to find the opposite reciprocal of a number: Start with Find its Write thea fraction reciprocal opp. reciprocalStart with Find its Write itsan integer reciprocal opp. reciprocal
8 Writing Equations for Perpendicular Lines Find an equation of the line that contains (0 , -2) and is perpendicular to y = 5x + 3.Step 1- Identify the slope of the given line.m = 5Step 2 – Find the opposite reciprocal of the slope:Step 3 – Use the slope-intercept form to write an equation.
9 More Practice!!! Textbook – p. 314 #2 – 30 even. Homework – Worksheet 6.5.