Mathematical Functions; Factorial - HP -34C Owner's Handbook Manual

24 Specific Features of the HP-34C
Mathematical Functions
Factorial
When the number in the X-register is a nonnegative integer n, pressing
(x1gives you the factorial of n, which is denoted n/ and defined as the
product of the integers from 1 to n. This function enables you to quickly
and easily solve permutations and combinations.
Example: Willie's Widget Works
wants a photograph of its product line
for advertising. How many different
ways can the photographer arrange their
eight widget models?
Solution: The number of arrangements is given by
Bl =8 XT7TX6X5X4X3X2X]1
Keystrokes Display
8 MY 40,320.0000 The photographer can ar-
range the widgets 40,320
different ways.
Example: The photographer looks through her viewfinder and decides
that she can show only five widgets if her camera is to capture the
intricate details of the widgets on film. How many different sets of five
widgets can she select from the eight?
Solution: The number of sets is given by
8!
(8 = 5)! 5!