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the_doors
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Homework Statement
for example: ##\frac{\partial(F^{ab}F_{ab})}{ \partial g^{ab}} ## where F_{ab} is electromagnetic tensor.
or ##\frac{\partial N_{a}}{\partial g^{ab}}## where ##N_{a}(x^{b}) ## is a vector field.
Homework Equations
The Attempt at a Solution
i saw people write ##F^{ab}F_{ab}## as ## g^{ca}g^{db}F_{cd} F_{ab}## and say we write the term in a way that exposes the dependence on the metric. but exactly what it means ?