Answer
Axis of symmetry: x=-2
Vertex: (-2,13)
Work Step by Step
$y = -4x^{2} - 16x - 3$
The standard form for a quadratic equation is
$y = ax^{2} + bx + c$ So a= -4, b= -16, and c= -2
Axis of symmetry:
The formula for axis of symmetry is
$x= \frac{-b}{2a}$
$x= \frac{-(-16)}{2(-4)}$
$x= \frac{16}{-8}$
x= -2
Vertex:
Plug in the x value of the axis of symmetry to find the y value of the vertex.
$y = -4x^{2} - 16x - 3$
$y = -4(-2)^{2} - 16(-2) - 3$
y= -16 + 32 -3
y= 13
The vertex is (-2,13)
