Question

What is the equation of the quadratic graph with a focus of (−4, seventeen eighths ) and a directrix of y = fifteen eighths

Answer 1

Standard form for a parabola:
( x - h )² = 4 p ( y - k )
Vertex: ( h, k ) = ( -4, 2 )
Displacement from vertex to focus:
p = 2/8 = 1/4
( x + 4 )² = 4 · 1/4 ( y - 2 )
y = ( x + 4 )² + 2
or general form:
x² + 8 x - y + 18 = 0