Answer
(a) $(\pm2\sqrt 2,0)$, $(0,-8)$, (b) symmetric with respect to the y-axis. (c) See graph.
Work Step by Step
(a) Given $y=x^2-8$, we can find the x-intercept(s) (let y=0) as $(\pm2\sqrt 2,0)$, y-intercept(s) (let x=0) as $(0,-8)$,
(b) To test symmetry, replace $(x,y)$ with $(x,-y)$ (x-axis symmetry), or $(-x,y)$ (y-axis symmetry), or $(-x,-y)$ (origin symmetry), and due to the $x^2$ term, we can find the function is symmetric with respect to the y-axis.
(c) See graph.