Microsoft Office Tutorials and References

In Depth Information

The trigonometric functions all assume radians for angles (not degrees). Use the

RADIANS function to convert degrees to radians.

Volatile functions

Some Excel functions belong to a special class of functions called
volatile.
Excel recalculates a volatile function

whenever it recalculates the workbook, even if the formula that contains the function is not involved in the recalcu-

lation.

The RAND function represents an example of a volatile function because it generates a new random number

every time Excel calculates the worksheet. Other volatile functions include

• CELL

• INDIRECT

• INFO

• NOW

• OFFSET

• TODAY

As a side effect of using these volatile functions, Excel always prompts you to save the workbook when you close

it, even if you made no changes to it. For example, if you open a workbook that contains any of these volatile

functions, scroll around a bit (but don't change anything) and then close the file. Excel asks whether you want to

save the workbook.

You can circumvent this behavior by using the Manual Recalculation mode, with the Recalculate Before Save op-

tion turned off. Change the recalculation mode in the Calculate section of the Formulas tab in the Excel Options

dialog box (choose File⇒Options).

Statistical functions

The functions in this category perform statistical analysis on ranges of data. For example, you can calculate stat-

istics such as mean, mode, standard deviation, and variance.

Lookup and reference functions

Functions in this category are used to find (look up) values in lists or tables. A common example is a tax table.

For example, you can use the VLOOKUP function to determine a tax rate for a particular income level.

Database functions

Functions in this category are useful when you need to summarize data in a list (also known as a
worksheet

database
) that meets specific criteria. For example, assume you have a list that contains monthly sales informa-

tion. You can use the DCOUNT function to count the number of records that describe sales in the Northern re-

gion with a value greater than 10,000.