> 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
This is called the geometric series, if you wish to look it up in a
math book.
For the series
1 + r + r^2 + r^3 + ... + r^(n-1)
the formula is
(1 - r^n)/(1 - r)
If you take n to be infinite the formula becomes
1 / (1 - r)
But! It only converges for -1 < r < 1.
Jim
------------------- ---------------------- --------------------
| Jim Cobb | 540 Arapeen Dr. #100 | [EMAIL PROTECTED] |
| Parametric | Salt Lake City, UT | (801)-588-4632 |
| Technology Corp. | 84108-1202 | Fax (801)-588-4650 |
------------------- ---------------------- --------------------
See when the Government spends money, it creates jobs; whereas when
money is left in the hands of Taxpayers, God only knows what they do
with it. Bake it into pies probably. Anything to avoid creating
jobs. -- Dave Barry
