2.2 Parallel and Perpendicular Lines and Circles Slopes and Parallel Lines • If two nonvertical lines are parallel, then they have the same slopes. • If two distinct nonvertical lines have the same slope, then they are parallel. • Two distinct vertical lines, with undefined slopes, are parallel.
Solution X1=-2 Y1=-7
What is the slope of the line? Given equation Slope of the line is –5.
Slopes and Perpendicular Lines • If two nonvertical lines are perpendicular, then the product of their slopes is –1. • If the product of the slopes of two lines is –1, then lines are perpendicular. • A horizontal line having zero slope is perpendicular to a vertical line having undefined slope.
Solution Solve the given equation for y. Slope is –3/2.
Definition of a Circle A circle is the set of all points in a plane that are equidistant from a fixed point called the center. The fixed distance from the circle’s center to any point on the circle is called the radius.
The Standard Form of the Equation of a Circle Center Any point on the circle
r=2 h=-4 k=-2