1. Section 2.4

2. X-axis: replace y with –y. Simplify. If you get an equation = to what you started with, the function is symmetric to the x-axis. Y-axis: replace x with –x. Simplify. If you get an equation = to what you started with, the function is symmetric to the y-axis. Origin: replace x with –x AND y with –y. Simplify. If you get an equation = to what you started with, the function is symmetric to the origin.

3. Test for symmetry: y = |x| - 2 X-axis: -y = |x| - 2y = -|x| + 2 This is not the same, so the function is not symmetric to the x-axis. Y-axis: y = |-x| - 2y = |x| - 2 This is the same, so the function is symmetric to the y-axis. Origin: -y = |-x| - 2y = -|x| + 2 This is not the same, so the function is not symmetric to the origin.

4. Test for symmetry: 5x – 5y = 0 X-axis: no Y-axis: no Origin: yes

5. A function is EVEN if it is symmetric to the Y-axis. A function is ODD if it is symmetric to the Origin.

6. Page 214 2 – 26 and 34 – 48 evens