Homework Help: Divergence homework problem help

1. Jul 19, 2014

manimaran1605

1. The problem statement, all variables and given/known data

How divergence of r (cap)/ |r|^2 is equal to zero?

2. Relevant equations

r(cap)= x(cap)+y(cap)+z(cap)

|r|^2 as x^2+y^2+z^2

3. The attempt at a solution

I tried the problem and end up with with a different solution I took r(cap)= x(cap)+y(cap)+z(cap)
|r|^2 as x^2+y^2+z^2. Tell me where i went wrong?

where r(cap) is unit vector of r vector
|r|^2 is the square of modulus of r

2. Jul 19, 2014

Quesadilla

Could you please provide the calculation that lead you to the wrong answer? It is hard to pinpoint where you went wrong otherwise.

3. Jul 19, 2014

vela

Staff Emeritus
You didn't differentiate correctly. Show your work.

4. Jul 19, 2014

manimaran1605

Here's my attempt to the problem

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5. Jul 20, 2014

Quesadilla

Well $\mathbf{\hat r} = \mathbf{\hat x} + \mathbf{\hat y} + \mathbf{\hat z}$ seems false. You have $\mathbf{r} = (x,y,z)$. Work from there.

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