Respuesta :

Complete the square: 
y = 3x^2 - 12x + 4 
y = 3(x^2 - 4x) + 4 
y = 3(x^2 - 4x + 4 - 4) + 4 
y = 3(x^2 - 4x + 4) - 12 + 4 
y = 3(x - 2)^2 - 8
The vertex form of any function is : f(x) = a(x-h)^2 + k
 Hence the correct option would be: A): "
-3(x-2)^2-9"