Answer
$(a)$ Symmetry with respect to $y$-axis
$(b)$ $x$-intercept $A(-3,0)$ and $B(3,0)$
$y$-intercept $C(0,9)$
Work Step by Step
$(a)$ As we can see from the image of the graph above, it is symmetrical with respect to the $y$-axis.
Algebraically, if we replace $x$ by $-x$ equation will be still equivalent to the original one.
$(b)$
$x$-intercept happens when $y=0$
$9-x^2=0$
$x^2=9$
$x=±3$
$A(-3,0)$ and $B(3,0)$
$y$-intercept happens when $x=0$
$y=9-0^2=9$
$C(0,9)$
