CAPE Pure Mathematics Unit 1 · 2008 (T&T) · Paper 1 · Question Q16

The radius of the circle 2x^2 + 2y^2 - 4x + 12y + 11 = 0 is

1. (A)\sqrt{29}
2. (B)\sqrt{51}
3. (C)\sqrt{\frac{9}{2}}
4. (D)\sqrt{11}