Hi. My class notes define ( gradu) like this :

(all the x are tensor products, and the d's are partial derivatives)

gradu=delxu

= (du/dxq) xeq

= (d/dxq)(upep) xeq

= (dup/dxq)ep xeq

whereuis a vector function ofx, and {ei} are basis vectors.

I'm confused about how theeq is put on the right hand side of the tensor product - seems to me it should be on the left, since it's associated withdel, and notu.

That is, I think it should be:

delxu

= eq d/dxq x upep

= (dup/dxq)eq xep

i.e. withep andeq the other way around to my notes. This is also how my textbook seems to define it.

So my question is, does the order ofep andeq make a difference? It seems to me it would result in a different matrix (the transpose??), but I'm not sure.

If they're different, which definition is correct?

Thanks,

~squiggles