[tex]3x^{2} - 12x + 12[/tex]
Get the x-coordinate of the vertex with the equation -b/2a.
[tex]\frac{-(-12)}{2(3)} = \frac{12}{6} = 2[/tex]
Plug this in and solve for y to get the y-coordinate of the vertex.
[tex]y = 3(2)^{2} - 12(2) + 12\\y = 6^{2} - 24 + 12\\y = 36 - 24 + 12\\y = 12 + 12\\y = 24[/tex]
The coordinates of the vertex are (2,24).