(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

let R be the separation vector from (a,b,c) to (x,y,z) and r be the magnitude of R.

Show that: del(1/r) = -R/r^2

2. Relevant equations

del is the gradient operator

3. The attempt at a solution

The problem is that I keep getting a 3/2 power in the denominator when I calculate the left hand side.

r = sqrt((x-a)^2 + (y-b)^2 + (z-c)^2)

1/r = ((x-a)^2 + (y-b)^2 + (z-c)^2)^-0.5

del(1/r) = -R/[(x-a)^2 + (y-b)^2 + (z-c)^2]^(3/2)

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# Homework Help: Del(1/r) = -R/r^2

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