Simplify delta(ij)delta(ij). The (ij) parts should be read as subscripts to the delta.

Can anyone give me any guidance on how to do this?

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- Mar 6th 2008, 10:30 AMYerobiSuffix Notation
Simplify delta(ij)delta(ij). The (ij) parts should be read as subscripts to the delta.

Can anyone give me any guidance on how to do this? - Mar 6th 2008, 12:12 PMtopsquark
$\displaystyle \delta_{ij} \delta_{ij} = \sum_{i,j = 1}^n \delta_{ij} \delta_{ij}$

by the Einstein convention.

Now, you know that $\displaystyle \delta_{ij} = 1$ only if i = j, so what is the sum of this series? (ie. how many times in the above sum do we get i = j?)

-Dan - Mar 6th 2008, 04:54 PMYerobi
'n' number of times?

- Mar 9th 2008, 05:25 AMYerobi
I'm just a bit confused on what form the answer should take? Will it be a constant?