- #1
scotty_le_b
- 19
- 0
Homework Statement
Without explicit calculation, argue why the following expression cannot be correct: $$\nabla \times (\mathbf{c} \times \mathbf{r}) = c_{2}\mathbf{e_{1}}+c_{1}\mathbf{e_{2}}+c_{3}\mathbf{e_{3}}$$ where ##\mathbf{c}## is a constant vector and ##\mathbf{r}## is the position vector.
Homework Equations
The Attempt at a Solution
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So I can do the explicit calculation to see that in fact the curl should be parallel to the vector ##\mathbf{c}## but then I struggle to provide an argument for why this should be so without the calculation.
I think that the incorrect solution has flipped the vector ##\mathbf{c}## in the x-y plane but left the z component unchanged. The position vector treats all directions equally so it seems strange that the z-component of ##\mathbf{c}## should be unchanged by this operation. However, I am unable to explain why this solution can't be true.