SOLUTION: Write an equation of a parabola with a vertex at the origin and a directrix at y = 5. (a) x=5y^2 (b) x=-1/20y^2 (c) y=-1/20x^2 (d) y=-20x^2

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Write an equation of a parabola with a vertex at the origin and a directrix at y = 5. (a) x=5y^2 (b) x=-1/20y^2 (c) y=-1/20x^2 (d) y=-20x^2      Log On

Hi

The standard form is , where the focus is (h,k + p) 

vertex at the origin and a directrix at y = 5. p = -5 (focus is (0,-5) 

 x^2 = -20y  OR y = (-1/20)x^2