If equation of a sphere is 2(x2 + y2 + z2) – 4x – 8y + 12z – 7 = 0 and one extremity of its diameter is (2, –1, 1), then the other extremity of diameter of the sphere will be
Answer & explanation
Correct answer: option 3
The centre of the sphere is (1, 2, –3) so if other extremity of diameter is (x1, y1, z1), then
$\frac{x_1+2}{2}=1, \frac{y_1-1}{2}=2, \frac{z_1+1}{2}=-3$
∴ Required point is (0, 5, 7).
Hence (3) is the correct answer.