FACT function

Description

Factorial function. FACT(n) returns the factorial of n. The factorial of a number n, n!, is equal to 1*2*3*...*n.

$$ n! = \prod_{k=1}^n k $$

If the argument n is not an integer, it is trunctated.

The argument n cannot be negative.

If n is larger than 170, the function overflows and returns an error (consider using the GammaLn function for calculations).

The argument n can be a real number or a matrix. When it is a matrix, the function returns a matrix with the same dimensions and with the FACT function applied to all elements.

Example

FACT(5) equals 120 (=1*2*3*4*5)

Calculator

Graph

Function:	FACT()
	X-axis	Y-axis
Minimum:	Minimum X	Minimum Y
Maximum:	Maximum X	Maximum Y

Enter the argument(s) for the function, including the symbol x.
Enter the minimum and maximum for the X-axis and for the Y-axis.
To let the software define the Y-axis automatically, leave both input fields for the Y-axis empty.

See also

• Beta, Gamma, factorial and combination functions
• FACTDOUBLE Double factorial function

External links

• Factorial on Wikipedia.