Symmetry of graphs

[pencil]

Please help me prove that if a graph is symmetric with respect to the x-axis and to the y-axis,then it is symmetric with respect to the origin. I tried to post this in math stack exchange and it gives me an error "your question does not meet our quality standards" even though i was descriptive and i have seen this error many times.

[rcfox]

If you ask other people to do your homework for you, you'll never learn. Go back to math.stackexhange, and provide the solution up to the point where you're stuck, and specifically identify what's causing you trouble.

[maxdemarzi]

Draw a circle.

[pencil]

i think i found the solution http://math.stackexchange.com/questions/59526/symmetry-with-...