Question

Describe the sets of points in space whose coordinates satisfy the given inequalities or combinations of equations and inequalities.
$x^2+y^2+z^2\le 1$

Answer 1

As $x^2+y^2+z^2=1$ represents a sphere of radius having centre at $(0,0,0)$

$\Rightarrow x^2+y^2+z^2\le 1$ represents all points inside the sphere.