New to the Einstein notation, having trouble with basic calculations

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    Einstein notation
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SUMMARY

The discussion focuses on the application of Einstein notation in tensor calculations, specifically addressing the definitions of symmetric and antisymmetric tensors. The correct expressions for these tensors are provided: ##A^{(ab)}=\frac 12(A^{ab}+A^{ba})## for symmetric tensors and ##A^{[ab]}=\frac 12(A^{ab}-A^{ba})## for antisymmetric tensors. The importance of avoiding commas between indices is emphasized to prevent misinterpretation. Additionally, the correct lowering of indices on tensors is highlighted, particularly regarding the components of ##\eta_{ab##.

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Ineedhelpimbadatphys
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Homework Statement
picture below.
Relevant Equations
no equations, but I am most interested in c), d), g) and e). I would like to know if my attempts are correct. If not, what am I doing wrong?
We are using minkowski metric.
IMG_2210.jpeg
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IMG_2518.jpeg
 

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I haven't checked your arithmetic, but (c) seems correct, if long-winded. You could just say ##A^{(ab)}=\frac 12(A^{ab}+A^{ba})## by definition.

Similarly (d), where you can just say ##A^{[ab]}=\frac 12(A^{ab}-A^{ba})## by definition. I suspect going the long way round got you into a pickle here, because you've somehow ended up with extra factors of the metric that shouldn't be there. (By the way, don't put commas between indices. Some people use ##V_{a,b}## as shorthand for ##\frac{\partial}{\partial x_b}V_a##, and you're liable to be misinterpreted.)

Your approach to (g) and (h) (did you mean (h) or (e)?) appears correct, but I'm not sure you've lowered indices correctly on the tensor. What are the components of ##\eta_{ab}## in your convention?
 

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