Question

Vector differentiation stuff?

Answer 1

Verify the identity (in cartesian coords)
\[\vec{\nabla} \times (\vec{\nabla} \times \vec{A}(\vec{r}))=\vec{\nabla}(\vec{\nabla} \cdot \vec{A}(\vec{r}))-\vec{\nabla}^2 \vec{A}(\vec{r})\]

Answer 2

I have an attempt but I just don't know how to get it to work right. I get an expression on the left with 12 terms and an expressin on the right of something else. Idk?

Answer 3

I forgot this stuff but maybe this helps you
http://www.youtube.com/watch?v=P4edqL1r4DQ