Question

A) x = -2 B) y =2 C) y= -2

Answer 1

Answer:

Step-by-step explanation:

This is a positive parabola so it opens upwards. The equation for the directrix of this parabola is y = k - p. k is the second number in the vertex of the parabola which is (0, 0), but we need to solve for p.

The form that the parabola is currently in is

$y=a(x-h)^2+k$ so that means that $a=\frac{1}{8}$. We can use that to solve for p in the formula

$p=\frac{1}{4a}$ so

$p=\frac{1}{4(\frac{1}{8}) }$ which simplifies to

$p=\frac{1}{\frac{1}{2} }$ which gives us that

p = 2. Now to find the directrix:

y = k - p becomes

y = 0 - 2 so

y = -2, choice A.