d
step-by-step explanation:
any point (x, y) on the parabola is equidistant from the focus and the directrix
here focus = (0, 5) and directrix is y = - 1
using the distance formula
= | y + 1 |
squaring both sides
x² + (y - 5)² = (y + 1)² ← expand parenthesis on both sides
x² + y² - 10y + 25 = y² + 2y + 1
subtract y² + 2y + 1 from both sides
x² - 12y + 24 = 0 ← subtract x² from both sides
- 12y + 24 = - x² ← subtract 24 from both sides
- 12y = - x² - 24 ( divide all terms by - 12 )
y = x² + 2 → d