- #1

- 15

- 0

[tex] \frac{1}{|R-r|} [/tex]

when R>>r, but they are both vectors. We were told to expand in r/R but I did the step below and I'm not sure where to go from there

I got to

[tex] \frac{1}{R \sqrt{1 - (2R.r)/R^2 + (r^2)/(R^2)}} [/tex]

I also know the result in first order is

[tex] \frac{1}{R} + \frac{R.r}{R^3} [/tex]