Question

True or False?

A sphere with center `P(x_0, y_0, z_0)` and radius `r` consists of all points `(x, y, z)` that satisfy the inequality `(x-x_0)^2+(y-y_0)^2+(z - z_0)^{2} <= r^2`.

Answer

True.

`<=` sign means that all points on the boundary of the sphere satisfy inequality and also all points inside the sphere.