5 Vector Field Proofs - apparently easy

thomas49th
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Homework Statement


http://gyazo.com/94783c14f2d2d05e62e479ab33c73830


Homework Equations


I know the dot product and cross product, but even for the first one I don't see how either helps.



The Attempt at a Solution


1. the gradient of the 2 scalars multiplied together (not crossed or dotted just multiplied)
I know that the derivative of a scalar is a vector, but that won't help here

Can someone put me out of my misery?
Thomas
 
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