Answer
Please see the graph.
Work Step by Step
Three points on the curve:
$y=3x^2-7$
Line of symmetry:
$x=-b/2a$
$x=-1*0/2*3$
$x=0/6 = 0$
$y=3x^2-7$
$y=3*(0^2)-7$
$y=3*0-7$
$y=-7$
$(0,-7)$
Let $x=3$:
$y=3x^2-7$
$y=3*3^2-7$
$y=3*9-7$
$y=27-7$
$y=20$
$(3,20)$
Since $(3,20)$ is three units from the axis of symmetry, we also know that $(-3,20)$ is also three units from the axis of symmetry and on the line.
