You know what the divergence theorem is, you can apply it and you conceptually understand it. This tutorial will actually prove it to you (references types of regions which are covered in the "types of regions in 3d" tutorial.
6809_Divergence_theorem_proof_part_3_.html
6808_Divergence_theorem_proof_part_2_.html
6811_Divergence_theorem_proof_part_5_.html
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