HP 35s Scientific manual Probability Functions, Factorial, Gamma

Probability Functions

￿Factorial

To calculate the factorial of a displayed non-negative integer x (0 ≤ x ≤ 253), press

*(the right–shifted key).

￿Gamma

To calculate the gamma function of a noninteger x, Γ(x), key in (x – 1) and press

*. The x! function calculates Γ(x + 1). The value for x cannot be a negative integer.

Probability

￿Combinations

To calculate the number of possible sets of n items taken r at a time, enter n first,

x, then r (nonnegative integers only). No item occurs more than once in a set, and different orders of the same r items are not counted separately.

￿Permutations

To calculate the number of possible arrangements of n items taken r at a time, enter n first, {, then r (nonnegative integers only). No item occurs more than once in an arrangement, and different orders of the same r items are counted separately.

￿Seed

To store the number in x as a new seed for the random number generator, press .

￿Random number generator

To generate a random number in the range 0 < x < 1, press . (The number is part of a uniformly–distributed pseudo–random number sequence. It passes the spectral test of D. Knuth, The Art of Computer Programming, vol. 2, Seminumerical Algorithms, London: Addison Wesley, 1981.)

Real–Number Functions 4-15