- #1
Susanne217
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Homework Statement
I have these three series here
[tex]\sum_{n=2}^{\infty} a_n \cdot z^n - \sum_{n=1}^{\infty} a_n \cdot z^{n+1} + \sum_{n=0}^{\infty} a_n \cdot z^{n+2}[/tex]
what I would like to do is to add the together as one sum representation
The Attempt at a Solution
From what I can see the commen sum of three is
[tex]\sum_{n=0}^{\infty} (a_{n+2} - a_{n+1} +a_{n})z^n[/tex] is that right?
What I don't remember do I add the index's together or subtract them?
If not please direct to a webpage with rules on howto do the above right :) Cause I have a whole in my knowledge then regarding to above :(
Susanne
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