Question

What is the equation of a parabola with a vertex at (0, 0) and a directrix x = -4?

Answer 1

the distance between the vertex \((0,0)\) and the directrix is 4
because it is open to the right it looks like \((y-k)^2=4p(x-h)\) and in this case \(h=k=0\) and \(p=4\) so you get
\[y^2=12x

Answer 2

whoa that was wrong \(y^2=4\times 4x\) or \(y^2=16x\)

Answer 3

\[x=\frac{ 1 }{ 16 }y ^{2} ?\] is the answer?

Answer 4

yes, that would be the same