Answer
Refer to the curve in Black in Graph I

Work Step by Step
For $y = 3x^2 - 2,$
when
$x = 2, y = 10;$
$x = 1, y = 1;$
$x = 0, y = -2;$
$x = -1, y = 1;$
$x = -2, y = 10$
As seen, $y = 3x^2 - 2$ is the vertical stretching of $y = x^2$ by 3 times and then with a vertical translation of 2 units down.
Domain = $(−\infty, \infty)$
Range = $[-2, \infty)$