My next section is a bit different and once again I have no clue what to do. In the book it says :

"Find the coordinates of the vertex then decide if the parabola has a minimum or maximum value."

Ex.1

f(x) = x^2 - 4x + 4

Ex. 2

f(x) = -x^2 - 8x - 16

Can you tell me what to do here?