5 Vector Field Proofs - apparently easy

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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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The ith component of ##\nabla(\phi\psi)## is given by ##\frac{\partial}{\partial x_i} (\phi\psi)##. That derivative is the regular old derivative you know and love, so what do you get when you apply the product rule?