Question

What is the axis of symmetry and vertex for the graph `y=4x^2-4x-15`?

Answer 1

`Vertex (1/2, -16)`

Explanation:

`y = 4x^2 - 4x - 15`
x-coordinate of vertex , and of the axis of symmetry:
`x = -b/(2a) = 4/8 = 1/2`
y-coordinate of vertex:
`y(1/2) = 4(1/4) - 4(1/2) - 15 = - 16`
`Vertex (1/2, -16)`
graph{4x^2 - 4x - 15 [-40, 40, -20, 20]}