The factors of the expression are :
y = (x - 2)(x - 6)
The x-intercepts are found by putting y = 0.
Therefore the x-intercepts are at (2, 0) and (6, 0).
The x value of the vertex is (2 + 6)/2 = 4.
f(4) = 16 -32 +12 = -4.
The coordinates of the vertex are (4, -4).
