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## Main Question or Discussion Point

**HELP PLEASE!!! Quick and simple!**

Hey I was wondering if you'll could help. I was told that this is a simple proof but have been working on it for ages and cant get it:

Suppose u is a [tex]C^{2}[/tex] function in [tex]R^{n}[/tex]. Given an nxn matrix, A define v(x):= u(Ax). Show that ([tex]\nabla[/tex]v)(x) = [tex]A^{T}[/tex] . [tex]\nabla[/tex]u(Ax)

(Note the grad u(Ax) isn't supposed to be superscripted I just dont know how to put it in the same line!)

Pleaseeee help!!

Thanks