A Solar Oven Uses a Parabolic Reflector to Focus the Sun's

Multiple Choice

A solar oven uses a parabolic reflector to focus the sun's rays at a point 5 inches from the vertex of the reflector (see figure) .Write an equation for a cross section of the oven's reflector with its focus on the positive y axis and its vertex at the origin. L = 5 inches

A) $y = 5 x ^ { 2 }$
B) $x ^ { 2 } = 5 y$
C) $y = 20 x ^ { 2 }$
D) $x ^ { 2 } = 20 y$
E) ​ $y = \frac { 1 } { 5 } x ^ { 2 }$