Geometry 3 6 Parallel Lines in the Coordinate

Geometry 3. 6 Parallel Lines in the Coordinate Plane

SLOPE

Slope is usually represented by the variable m Always start with the point farthest right

Examples Find the slope that passes through the following points. 1. (0, 6) and (5, 2) 2. (-3, 0) and (4, 7)

Find the slope of these two lines

Postulate 17: SLOPES OF PARALLEL LINES In a coordinate plane, two nonvertical lines are parallel if and only if they have the same slope. Any two vertical lines are parallel

Example Line p passes through (0, -3) and (1, -2). Line m passes through (5, 4) and (-4, -4). Line n passes through (-6, -1) and (3, 7). Find the slope of each line. Which lines are parallel?

Slope-Intercept Form The y-intercept is the y-coordinate of the point where the line crosses the y-axis.

Writing an Equation of a Line Write an equation for the following lines with the given information. 1. Passes through (2, 3) and has a slope of 5. 2. Passes through (4, 9) and has a slope of -2. 3. Passes through (20, 5) and has a slope of 3/10.

Writing an Equation of a Parallel Line n has the equation y = (-1/3)x – 1. Line m is parallel to n and passes through the point (3, 2). Write an equation of line m.

Example Line a has the equation y = (2/5)x + 3. Line b is parallel to a and passes through the point (-5, 0). Write an equation for line b.