About Nabla and index notation

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Nabla in index notation can be represented as $$\partial_i e_i$$, but treating it as a vector when calculating curl, divergence, or gradient is an 'abuse of notation.' While this approach may serve as a helpful mnemonic for beginners, it is important to recognize that it is not strictly correct, as the gradient $$\nabla f$$ is technically a covector. Understanding the nuances of vector calculus and notation can be challenging, especially for beginners, but it is crucial to avoid confusion in advanced applications. The discussion emphasizes the importance of bridging practical knowledge of vector calculus with proper notation. Overall, clarity in notation will aid in mastering vector identities as the course progresses.
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Homework Statement


Can I, for all purposes, say that Nabla, on index notation, is $$\partial_i e_i$$ and treat it like a vector when calculating curl, divergence or gradient?
For example, saying that $$\nabla \times \vec{V} = \partial_i \hat{e}_i \times V_j \hat{e}_j = \partial_i V_j (\hat{e}_i \times \hat{e}_j) = \partial_i V_j \epsilon_{ijk} \hat{e}_k$$
I have a feeling that is wrong, I've found all kinds of variations of this notation on the internet, almost no one seems to use the unit vectors, and that confuses me, being a total beginner on this kind of notation.

Homework Equations


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The Attempt at a Solution


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It's an 'abuse of notation', but it can be useful as a mnemonic. If it helps you remember the formulas, that's fine. But try not to lose sight of the fact that it is not strictly correct. For instance ##\nabla f## is not strictly a vector (it's a covector, aka one-form or dual vector). You probably don't need to understand nuances like that yet if you're just starting but it's good to remember that the notation is just a mnemonic, to avoid confusion later on.
 
Yes i have very clear what do gradients or divergences do...in a practical way (direction of max change, and flux per EDIT:volume unit :) i believe?) but I'm still struggling setting up the bridge between my vector calculus knowledge, physics knowledge, and this notation... But the course is only starting, and I'm trying to prove vector identities.

Thanks for the response :)
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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