Dummy Index

By Kardi Teknomo, PhD.

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Can I change that dummy index?

Yes, you can. Here is the example formula

Name of index and range is not always from 1 or from 0, it can start from any number. Index is dummy name. The name is not important; you can put any name as long as they are consistent.

Example

If we have a sequence of numbers then we can put index on the sequence such that , , , , , and

But you can also start the index from zero if you like such that

, , , , , and

Of course, the results are the same because actually they sum over the same sequence of numbers.

See Also: Kardi Teknomo's Tutorial

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Comments for this tutorial

This tutorial is copyrighted.

Preferable reference for this tutorial is

Teknomo, Kardi. Summation Tutorial. http://people.revoledu.com/kardi/tutorial/basicmath/sum/