Vector Analysis Identity simplification/manipulation

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SUMMARY

The discussion focuses on simplifying the expression \(\nabla\cdot(g\nabla \times (g\mathbf{G}))\) where \(\mathbf{G}(x,y,z)\) is an irrotational vector field and \(g(x,y,z)\) is a \(C^1\) function. Participants clarify that \(g\nabla\) should not be treated as a vector but as an operator. The identity \(\nabla\cdot(\mathbf{F} \times \mathbf{G}) = \mathbf{G}\cdot(\nabla\times\mathbf{F}) - \mathbf{F}\cdot(\nabla\times\mathbf{G})\) is referenced to aid in the simplification process. The irrotational property of \(\mathbf{G}\) indicates that \(\nabla\times\mathbf{G} = 0\), which is crucial for further simplification.

PREREQUISITES
  • Understanding of vector calculus, specifically vector identities.
  • Familiarity with the concepts of irrotational vector fields.
  • Knowledge of the gradient, divergence, and curl operators.
  • Proficiency in manipulating \(C^1\) functions in vector calculus.
NEXT STEPS
  • Study the '14 basic vector identities' in detail.
  • Learn about the properties of irrotational vector fields and their implications.
  • Research the application of curl and divergence in vector calculus.
  • Practice simplifying expressions involving operators and vector fields.
USEFUL FOR

Students and professionals in mathematics, physics, or engineering who are working with vector calculus, particularly those focusing on vector field analysis and simplification techniques.

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Homework Statement



Let \mathbf{G}(x,y,z) be an irrotational vector field and g(x,y,z) a C^1 function. Use vector identities to simplify:

\nabla\cdot(g\nabla \times (g\mathbf{G}))


Homework Equations



The '14 basic vector identities'

The Attempt at a Solution



I tried using the identity \nabla\cdot(\mathbf{F} \times \mathbf{G}) = \mathbf{G}\cdot(\nabla\times\mathbf{F}) - \mathbf{F}\cdot(\nabla\times\mathbf{G})

But I'm not sure if i can treat g\nabla as a vector?

Really I'm quite clueless.
 
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No, I wouldn't treat g\nabla as a vector, it's an operator. Start from the inside. You've got curl(gG). Irrotational tells you curl(G)=0. How does that let you simplify curl(gG)? BTW curl(X)=\nabla\times\mathbf{X}. div(X)=\nabla\cdot\mathbf{X}.
 
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