Chapter 9 - Quadratic Functions and Equations - 9-1 Quadratic Graphs and Their Properties - Practice and Problem-Solving Exercises - Page 551: 41

Vertex = $(0,-6)$ Axis of Symmetry is $x=0$

$Y = -3x^{2} - 6$ Use $\frac{-b}{2a}$ to find x coordinate $\frac{-0}{2a} = 0$ X coordinate = 0 Plug in the x coordinate to get the y coordinate $Y = -3*0^{2} - 6 = 0$ Y coordinate = 0 Axis of Symmetry is equal to x coordinate Axis of Symmetry is x = 0