Consider a function f = 1r̂ , where r is distance

Consider a function f = 1 r̂ , where r is distance from origin and rˆ is unit vector.
r²
, The divergence of this function over a sphere of radius R, which includes origin is.

Consider a function f =	1	r̂ , where r is distance from origin and rˆ is unit vector.
	r²