Final Answer:
The equation of the quadratic graph with a focus of (5, -1) and a directrix of y = 1 is (B) f(x) = 1/4(x-5)² + 1.
Step-by-step explanation:
Directrix and Focus: A parabola is defined as the set of all points equidistant to the focus and the directrix. Since the directrix is horizontal (y = 1), the parabola opens upwards and the axis of symmetry is vertical (x = 5).