- #1

- 247

- 11

## Homework Statement

prove grad(a.grad(r^-1))= -curl(a cross grad (r^-1))

## Homework Equations

curl(a x b)= (b dot grad)a - (a dot grad)b +a(div b) - b(div a )

## The Attempt at a Solution

Im trying to use index notation and get

di (aj (grad(r^-1))j)

=grad(r^-1) di(aj) +aj(di grad(r^-1))j

which is obviously not right. Ive tried attacking the problem from the reverse direction and haven't had much luck there either.

Thank you :)