Question

What is the equation of the axis of symmetry for the graph of `f(x) = -3x^2 - 6x + 4`?

Answer 1

Completing the square,

`f(x) = -3x^2 - 6x +4 = -3(x^2 + 2x) + 4 = -3(x^2 + 2x +1) +3 + 4 = -3(x + 1)^2 +7,`

so the axis of symmetry is `x=-1` and the vertex `(-1,7)`.