Question
Question: The centre of the circle r<sup>2</sup> = 2 – 4r cos θ + 6r sin θ is...
The centre of the circle r2 = 2 – 4r cos θ + 6r sin θ is
A
(2, 3)
B
(–2, 3)
C
(–2, –3)
D
(2, –3)
Answer
(–2, 3)
Explanation
Solution
Put x = r cos θ & y = r sin θ ⇒ x2 + y2 = 2 –4x + 6y
⇒ x2+y2 + 4x –6y – 2 = 0; ∴ Centre = (–2, 3)