Correct Answer - Option 1 : 6
Concept:
The distance 'd' between two points (x1, y1, z1) and (x2, y2, z2) in space is obtained by using the Pythagoras' Theorem twice:
d2 = (x1 - x2)2 + (y1 - y2)2 + (z1 - z2)2
Calculation:
Radius of a sphere is the distance between the centre of the sphere to any point on its surface.
Here the center is given to be (4, 4, -2) and the origin (0, 0, 0) is given to be a point on its surface.
∴ r2 = (4 - 0)2 + (4 - 0)2 + (-2 - 0)2 = 16 + 16 + 4 = 36
⇒ r = 6.
