Answer
(a) (h,k)
(b) Upward; minimum
(c) Downward; maximum
Work Step by Step
For a quadratic function in standard form:
f(x) = a(x-h)^2 + k
(a) the vertex is always (h,k)
(b) If a$\gt$0 this means that the parabola opens UPWARD with the vertex being on the bottom, thus if a$\gt$0 the vertex is the MINIMUM point of the parabola
(c) If a$\lt$0 this means the parabola opens DOWNWARD with the vertex on the top, therefore if a$\lt$0 the vertex is the MAXIMUM point of the parabola.
