Question

Which is the standard form of the equation of a parabola with a focus of (8, 0) and directrix x = –8?
y^2=-8x
y^2=8x
y^2=32x
y^2=-32x

Answer 1

The vertex is halfway between the focus (8,0) and directrix x = −8, so the vertex is (0,0). The focus relative to the vertex is at (p,0) with p = 8. The standard form for a parabola opening right is y^2 = 4px, so y^2 = 4·8·x = 32x.

Answer: y^2 = 32x.