Luckily, we already have 50% of our vertex from the work we did above in finding the axis of symmetry. By inputting the x-value, we will get a y-value, resulting in the ordered pair of the vertex.
4(-1/4)2+2(-1/4)-12 ... Use PEMDAS to solve
4(1/16)+2(-1/4)-12
(1/4)-(1/2)-12 = -12.25
The vertex is located at (-.25, -12.25).