| Figure A1 Half of the graph of a function |
If the function graphed in Figure A1 is even, then the value assigned to `-a` is the same as the value assigned to `a`, i.e., `text[(]-a,btext[)]` is on the graph. This means that the portion of the graph on the left side of the `y`-axis may be obtained from the portion on the right by rotating around the `y`-axis. On the other hand, if the function is odd, then the value assigned to `-a` is the negative of the value assigned to `a`, i.e., `text[(]-a,-btext[)]` is on the graph. This means that the portion of the graph on the left side of the `y`-axis may be obtained from the portion on the right by rotating around the `y`-axis and then rotating about the `x`-axis (or vice versa). See Figures A2 and A3 for the even and odd cases, respectively.
|
|
| Figure A2 An even function | Figure A3 An odd function |