The graph is symmetric about the origin if point (x,y) lie on the curce then point (-x,y) should also be on the curve.
For the equation y = sin x.
Substitute -x for x in the equation y = sin x.
[tex]\begin{gathered} y=\sin (-x) \\ =-\sin x \\ =-y \end{gathered}[/tex]So curve y = sinx is symmetric about the origin.
