SERIESSUM

See Also

Returns the sum of a power series based on the formula:

Equation

Many functions can be approximated by a power series expansion.

If this function is not available, and returns the #NAME? error, install and load the Analysis ToolPak add-in.

Show How?

On the Tools menu, click Add-Ins.
In the Add-Ins available list, select the Analysis ToolPak box, and then click OK.
If necessary, follow the instructions in the setup program.

Syntax

SERIESSUM(x,n,m,coefficients)

X is the input value to the power series.

N is the initial power to which you want to raise x.

M is the step by which to increase n for each term in the series.

Coefficients is a set of coefficients by which each successive power of x is multiplied. The number of values in coefficients determines the number of terms in the power series. For example, if there are three values in coefficients, then there will be three terms in the power series.

Remark

If any argument is nonnumeric, SERIESSUM returns the #VALUE! error value.

Example

The example may be easier to understand if you copy it to a blank worksheet.

Show How?

Create a blank workbook or worksheet.
Select the example in the Help topic. Do not select the row or column headers.

Selecting an example from Help
Press CTRL+C.
In the worksheet, select cell A1, and press CTRL+V.
To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Tools menu, point to Formula Auditing, and then click Formula Auditing Mode.

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A
Coefficients
=PI()/4
1
=-1/FACT(2)
=1/FACT(4)
=-1/FACT(6)
Formula	Description (Result)
=SERIESSUM(A2,0,2,A3:A6)	Approximation to the cosine of Pi/4 radians, or 45 degrees (0.707103)