Write an equation for the parabola with vertex at the origin.
-Through $( 6 , - 12 )$, opening downward
A) $y = \frac { 1 } { 3 } x ^ { 2 }$
B) $x = - \frac { 1 } { 3 } y ^ { 2 }$
C) $x ^ { 2 } = - \frac { 1 } { 3 }$
D) $x ^ { 2 } = - 3 y$

Question

Quizplus · Accepted Answer

The equation of a parabola with vertex at the origin and opening downward is $x^2 = -4py$. Given the point (6, -12), solving for p gives $p = \frac{3}{4}$, so the equation is $x^2 = -3y$.

Write an Equation for the Parabola with Vertex at the Origin