The equation of the sphere S is x² + y² + z² − 4x − 6y − 12z + k = 0. What is the radius of the sphere passing through origin and concentric with the sphere S?
A.7/2
B.5
C.7✓ Correct
D.Cannot be determined due to insufficient data
Explanation
Sphere S has center (2, 3, 6). A sphere concentric with S passing through origin has center (2, 3, 6) and radius = distance from (2, 3, 6) to origin = √(4 + 9 + 36) = √49 = 7.
💡 Practice unlimited NDA PYQs + AI-tracked progress on each topic. Sign up free →
More Three Dimensional Geometry - Sphere questions