Kenneth S. answered 04/27/16
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Expert Help in Algebra/Trig/(Pre)calculus to Guarantee Success in 2018
A quadratic function is a parabola, when graphed. If it has a minimum, then it's opening upwardly and the vertex coordinates are (h,k) at the minimum value of the function. Thus (h,k) = (2,-4).
The general equation is y - k = a(x - h)2 and you can substitute the coordinates (4,12) in for (x,y); then you will be able to determine the value of a.