Probability Functions - HP 39gII User Manual

H I N T

Probability functions

COMB
!
PERM
172
The results of POLYROOT will often not be easily seen in
Home due to the number of decimal places, especially if
they are complex numbers. It is better to store the results
of POLYROOT to a matrix.
For example, POLYROOT([1,0,0,-8]
store the three complex cube roots of 8 to matrix M1 as
a complex vector. Then you can see them by going to the
Matrix Catalog. You can also access them individually in
calculations by referring to M1(1), M1(2) etc.
Number of combinations (without regard to order) of n
things taken r at a time: n!/(r!(n-r)).
COMB(n, r)
Example:
COMB(5,2) returns 10. That is, there are ten
different ways that five things can be combined two
at a time.
Factorial of a positive integer. For non-integers, ! = Γ(x +
1). This calculates the gamma function.
value!
Example:
5! Returns 120
Number of permutations (with regard to order) of n things
taken r at a time: n!/(r!(n-r)!
PERM (n, r)
Example:
PERM(5,2) returns 20. That is, there are 20
different permutations of five things taken two at a
time.
M1 will
Using mathematical functions