# Explain why the divergence of each of the functions must be zero

## Homework Statement

the question is:
Without doing any calculations, explain why the divergence of each of the functions must be zero(Hint: consider what electric field these functions physically correspond to)
P.S: I make the unit vectors in bold.

A1=x

A2=ρ(1/ρ) with ρ>0

A3=r(1/r2) with r>0

## Homework Equations

I think we need to argue about the charge

## The Attempt at a Solution

for A1 , the electric field of A! is a plane, which constant, so divergence is zero.

for A2, it seems to be a line of charge but I don know how to argue for the divergence to be zero.

Same for A3

Can someone see what is going on?
B