Intercepts

• y-intercept: where the graph crosses the y-axis.• Algebraically – set x=0

• x-intercept: where the graph crosses the x-axis. • Algebraically – Set y=0.

Example:

Find the x- and y- intercepts of the graph

Symmetry of a Graph

1. The graph of an equation in x and y is symmetric with respect to the y-axis if replacing x by –x yields an equivalent equation.

Symmetry of a Graph

2. The graph of an equation in x andy is symmetric with respect to the x-axis if replacing y by –y yields an equivalent equation.

Symmetry of a Graph

3. The graph of an equation in xand yis symmetric with respect to the origin if replacing x by –x and y by –y yields an equivalent equation (unchanged by a rotation of 180°).

Example

Test the graph of for symmetry.

Example

Find all points of intersection of the graphs of and .

Example Continued

Definition of the Slope of a Line

Equations of Lines

Parallel and Perpendicular Lines