Question
Question: The equation of the parabola whose vertex is at (2, –1) and focus at (2, –3) is...
The equation of the parabola whose vertex is at (2, –1) and focus at (2, –3) is
A
x2 + 4x – 8y –12 = 0
B
x2 – 4x + 8y + 12 = 0
C
x2 + 8y = 12
D
x2 – 4x + 12 = 0
Answer
x2 – 4x + 8y + 12 = 0
Explanation
Solution
Let the equation X2 = –4ay
(x –2)2 = –4(2) (y + 1)
x2 –4x + 8y + 12 = 0