Objective: To write equations of parallel and perpendicular lines. Ch 5.6 Objective: To write equations of parallel and perpendicular lines.

Definitions Parallel Lines have the SAME slope Perpendicular Lines Have opposite and reciprocal slopes { { Sign changes “flip” the fraction

Determine if the following pairs of equations are Parallel, perpendicular, or neither: 1 2 1 2 1) y = x + 2 and y = x - 1 Parallel 2 3 - 3 2 2) y = x – 3 and y = x + 2 Perpendicular 1 4 3) y = 4x + 1 and y = x - 3 Perpendicular 2 3 2 3 4) y = x – 1 and y = x + 2 Parallel 2 5 3 5 5) y = x – 1 and y = x + 2 Neither

Graph the following on the coordinate plane. y x Parallel lines have the same slope.

Find the equation of a line in standard form that is parallel to 3x - 5y = 10 and contains (-2,6). (-2,6) 3x - 5y = 10 -3x -3x -5y = -3x + 10 -5 -5 or

Perpendicular lines have slopes that are Graph the following on the coordinate plane. y x Lines appear perpendicular Perpendicular lines have slopes that are opposite reciprocals

Find the following: Opposite Reciprocal Number Opposite Reciprocal 3 0.2 -8

Find the equation of a line in standard form that is perpendicular to 4y - x = 6 and contains (2,5). 4y - x = 6 (2,5) +x +x 4y = x + 6 4 4

Determine whether the slopes are perpendicular. 1) Yes, perpendicular. 2) No, not perpendicular. 3) Yes, perpendicular.

Find the equation of a line in standard form that is perpendicular to 3x + 5y = 7 and contains (-4,-8). (-4,-8) 3x + 5y = 7 -3x -3x 5y = -3x + 7 5 5 or