1. 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.

2. Example: Find the x- and y- intercepts of the graph

3. 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.

4. 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.

5. 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°).

6. Example Test the graph of for symmetry.

7. Example Find all points of intersection of the graphs of and.

8. Example Continued

9. Definition of the Slope of a Line

10. Equations of Lines

11. Parallel and Perpendicular Lines