## Precalculus: Mathematics for Calculus, 7th Edition

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.