You can put this solution on YOUR website! Symmetry of a Graph
f(x) = x^2-9
---------------------
f(-x) = (-x)^2 - 9 = x^2-9
---------------------
-f(-x) = -x^2+9
==========================
Since f(x) = f(-x) the graph is symmetric to the y axis.
----
Since f(x) is not equal to -f(-x) the graph is not symmetric to the origin.
============================================================================
Cheers,
Stan H.