-----Original Message-----
From: Tad Dunne <[EMAIL PROTECTED]>
To: Sundial List <[email protected]>
Date: Quarta-feira, 23 de Setembro de 1998 15:34
Subject: What's sum of series of increasing powers?
>Help!
>
>I'm working on an Excel spreadsheet and need a formula or function that
>will give,
>
>for an input A and B, the sum of all the powers of A for integers from
>1 to B.
>Example: 1.05 + 1.05 squared + 1.05 cubed ...
>
>Can anyone help me?
>
>-- Tad Dunne
>
>
Tad,
3^1+3^2+3^3+3^4+3^5 =
3^1+3^2+3^3+3^4+3^5+3^6-3^6 =
3^1+3^1*(3^1+3^2+3^3+3^4+3^5)-3^6
3^1+3^2+3^3+3^4+3^5 = 3^1+3^1*(3^1+3^2+3^3+3^4+3^5)-3^6
(3^1+3^2+3^3+3^4+3^5) - 3^1*(3^1+3^2+3^3+3^4+3^5) = 3^1-3^6
(3^1+3^2+3^3+3^4+3^5)*(1-3^1) = 3^1*(1-3^5)
3^1+3^2+3^3+3^4+3^5 = 3^1*(1-3^5)/(1-3^1)
jorge
