Documentation/How Tos/Calc: SERIESSUM function
Sums the first terms of a power series.
This function is only available if the Analysis AddIn is installed.
SERIESSUM(x; n; m; ar)
- A power series may be represented as:
- The SERIESSUM function calculates the sum of the first terms of such a series, where:
- x is the variable,
- n is the power of x for the first term,
- m is the increment by which the power of x increases with each term, and
- ar refers to a range containing the a coefficients of the terms to be included.
The following power series may be used to express the mathematical constant e raised to a power:
When x = 1, summing the terms in the series will approximate e. To sum the first 5 terms using SERIESSUM we should set:
- x = 1
- n = 0
- m = 1
- ar to B1:B5, where B1, B2, B3, B4, B5 contain respectively:
- = 1/FACT(0), = 1/FACT(1), = 1/FACT(2), = 1/FACT(3), = 1/FACT(4)
Now, using these values in the SERIESSUM function:
SERIESSUM(1; 0; 1; B1:B5)
- returns 2.70833333333333, an approximation of e ( = 2.71828182845904...). Using more terms would give a closer approximation.