<p>So they gave me a bunch of graphs and asked which one is symmetric about origin? How can i know? </p>
<p>If something is symmetric about the origin, then F(x,y) is equivalent to F(-x,-y)</p>
<p>@observeraffect or in more formal math language, f(-x) = -f(x)</p>
<p>It’s called odd symmetry if you want to google it. </p>
<p>More generally, something is symmetric about the origin if you can rotate it 180 degrees about the origin and produce the same image.</p>
<p>@BassGuitar It’s not only functions that can be symmetric about the origin. If (x,y) is on a graph symmetric about the origin, then so is (-x,-y).</p>
<p>Thanks everyone 
Got it now. </p>