HP 39gII

170 Using mathematical functions
numer Simplified Numerator. For the integers a and b, returns
the numerator of the fraction a/b after simplification.
numer(a/b)
Example:
numer(10/12) returns 5.
denom Simplified Denominator. For the integers a and b, returns
the denominator of the fraction a/b after simplification.
denom(a/b)
Example:
denom(10/12) returns 6.
List functions
These functions work on list data. See the chapter Lists for
details.
Loop functions
The loop functions display a result after evaluating an
expression a given number of times.
ITERATE Repeatedly for #times evaluates an expression in terms of
variable. The value for variable is updated each time,
starting with initialvalue.
ITERATE(expression, variable, initialvalue,
#times)
Example:
ITERATE(X
2
,X,2,3) returns 256
Σ Summation. Finds the sum of expression with respect to
variable from initialvalue to finalvalue.
Σ (expression, variable, initialvalue, finalvalue)
Example:
Σ(x
2
,x,1,5) returns 55.