Answer:
The vertex is (5, -9).
Explanation:
One way of approaching this problem consists of finding the roots. Seet the quadratic equal to zero and solve for x: {2, 8}.
The axis of symmetry is exactly halfway between 2 and 8: x = 5.
Now find the y-component of the vertex by evaluating f(5):
f(5) = (5 - 8)(5 - 2) = -9
The vertex is (5, -9). This is the minimum value of the function. The graph of this quadratic opens up.