Answer:
The equation of the parabola is (x + 4)² = -16(y + 1)
Step-by-step explanation:
The standard form of the equation of the parabola is (x - h)² = 4p(y - k), where
- The vertex of the parabola is (h, k)
- The directrix is at y = k - p
∵ The focus at (-4, -5)
∴ h = -4
∴ k + p = -5 ⇒ (1)
∵ The directrix at y = 3
∴ k - p = 3 ⇒ (2)
→ Add equations (1) and (2) to find k
∴ 2k = -2
→ Divide both sides by 2 to find k
∴ k = -1
→ Substitute it in equation (1) to find p
∵ -1 + p = -5
→ Add both sides by 1
∴ -1 + 1 + p = -5 + 1
∴ p = -4
→ Substitute the values of h, k, and p in the formula above
∵ (x - -4)² = 4(-4)(y - -1)
∴ (x + 4)² = -16(y + 1)
∴ The equation of the parabola is (x + 4)² = -16(y + 1)
