Gradient and Divergence in spherical coordinates

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AI Thread Summary
The discussion centers on the divergence of a vector field expressed in spherical coordinates, specifically the components involving er, e(θ), and e(φ). There is a disagreement regarding the expression for the vector field, with one participant presenting a different form for e(θ) and raising questions about the dimensional consistency of the scalar field. The conversation highlights the importance of using LaTeX for clarity in mathematical expressions. It is emphasized that the gradient can be derived in spherical coordinates through direct substitution and basic linear algebra, which also allows for the computation of divergence, curl, and the Laplacian. Overall, the thread focuses on the mathematical formulation and consistency of vector fields in spherical coordinates.
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Homework Statement
Hello, are my answers correct?

I had to calculate the gradient of f=z and f=xy in spherical coordinates.
My solution for f= z is: cos(θ) er+ (-sin(θ)) e(θ)

f=xy

rsin^2(θ)sin(2φ) er+ rcos(θ)cos(φ)sin(θ)sin(φ) e(θ)+ rcos(2φ)sin(θ) e(φ)

I also had to calculate the divergence of the following vectorfield (Image)

My result is: (scalarfield)

Sin^2(θ)cos^2(φ) er + rcos(2θ)cos^2(φ) e(θ)-rsin(θ)cos(2φ) e(φ)


Thanks in advance
Relevant Equations
er, e(θ) and e(φ) are the spherical base vectors
9527BE5E-8449-4D24-8FA2-A3BE2FC41DD0.jpeg

Vectorfield for the divergence
 
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physicss said:
rsin^2(θ)sin(2φ) er+ rcos(θ)cos(φ)sin(θ)sin(φ) e(θ)+ rcos(2φ)sin(θ) e(φ)
I get a slightly different ##\vec e_\theta##.
Please learn to use LaTeX.
 
physicss said:
My result is: (scalarfield)

Sin^2(θ)cos^2(φ) er + rcos(2θ)cos^2(φ) e(θ)-rsin(θ)cos(2φ) e(φ)
If it is a scalar, how come it has ##\vec e_r## etc?
I also note a dimensional inconsistency.
 
You can get the gradient in spherical (or any other) coordinates by direct substitution, using basic linear algebra. From there you can get div, curl, and the Laplacian just by vector operations:
 
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