Question
Question: The focus of the parabola x<sup>2</sup> - 2x - 8y - 23 = 0 is...
The focus of the parabola x2 - 2x - 8y - 23 = 0 is
A
(1, -1)
B
(1, 1)
C
(-1, 1)
D
(-1, -1)
Answer
(1, -1)
Explanation
Solution
The focus of the parabola (x – α)2 = 4a(y - β) is (α, a+β)
The given parabola is (x – 1)2 = 8(x+3)
∴ The focus is (1, 2+ -3) = (1, -1)