 So what does symmetry mean with respect to graphs? A graph can be symmetric about the x-axis. What's above is a reflection of what's below. Or it can be symmetric about the y-axis. What's to the right is a reflection of what's on the left. Or it could be symmetric about the origin. What's in a corner is a reflection of what's in the opposite corner. It can have any or all of these symmetries, or possibly none of these. For example, let's take a look at the graph shown. Now if we view the x-axis as a mirror, we see that what's above is not what's below. But if we view the y-axis as a mirror, we see that what's to the right is a reflection of what's on the left. And finally, if we view the origin as a mirror, we see that what's in one corner is not what's in the other corner. And so this graph is symmetric about the y-axis only. Or suppose a graph is symmetric about the x-axis, sketch the rest of the graph, given the part shown. Now with symmetry about the x-axis, the x-axis acts like a mirror. So whatever is above is reflected to the bottom.