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## Homework Statement

I want to show that:

Grad dot product with

__r__= 2/r

where:

__r__is the unit vector

**r**/r

**r**= x

**i**+ y

**j**+ z

**k**

r is magnitude of

**r**

## The Attempt at a Solution

I think the answer should be 3/r

since unit vector

__r__=

**r**/r,

__r__= (x/r)

**i**+ (y/r)

**j**+ (z/r)

**k**

then when I do grad dot

__r__I should get (1/r) + (1/r) + (1/r) = (3/r)

what do you think?