Question

The centre of the circle $r ^ { 2 } = 2 - 4 r \cos \theta + 6 r \sin \theta$ is

• A. (2, 3)
• B. (– 2, 3)
• C. (– 2, – 3)
• D. (2, – 3)

Answer 1

Answer: (B)

(– 2, 3)

Answer 2

Let r cos θ = x and r sin θ = y

Squaring and adding, we get $r ^ { 2 } = x ^ { 2 } + y ^ { 2 }$ .

Putting these values in given equation, $x ^ { 2 } + y ^ { 2 } = 2 - 4 x + 6 y$

Hence, centre of the circle = (–2, 3)