Microsoft Office Tutorials and References
In Depth Information
The EXP function
returns the e raised
to the power of the
FAC The FACT function returns the factorial of a number. The factorial of a number is equal to the
product of integers from 1 to number.
The NUMBER argument is the non-negative number you want the factorial of. If number is not
an integer, it is truncated (see the TRUNC function later in this chapter).
Example: FACT(4) equals 24, which is equivalent to =1*2*3*4 .
You also might want to calculate the sum of a series of factorials from n to m, where n and m
are positive integers. You can do this with a formula such as =FACT(n)+FACT(n+1)..+FACT(m)
but the formula might get a little long. Instead, you can use an array formula to perform this
task. This formula is of the form =SUM(FACT(ROW(n:m))) . As an example, the formula
=SUM(FACT(ROW(2:5))) returns 152, which is the sum of FACT(2) , FACT(3) , FACT(4) , and
FACT(5) . Notice the example in Figure 10.14.
The use of the ROW function with a RANGE argument allows you to create an array of numbers. The
array created by the formula ROW(1:10) is an array of numbers from 1 to 10.
To use this formula you must remember that it must be entered as an array formula (by
holding down the Ctrl and Shift keys when pressing Enter).
Returns the factorial of a number. For example 1*2*3 ….