HP 39gs - Manual (Page 162)

13-10 Using mathematical functions
EXP Natural exponential. This is more accurate than due
to limitations of the power function.
EXP(value)
EXPM1 Exponent minus 1 : . This is more accurate than
EXP when x is close to zero.
EXPM1(value)
LNP1 Natural log plus 1 : ln(x+1). This is more accurate than
the natural logarithm function when
x is close to zero.
LNP1(value)
List functions
These functions work on list data. See “List functions” on
page 16-6.
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
RECURSE Provides a method of defining a sequence without using
the Symbolic view of the Sequence aplet. If used with |
(“where”), RECURSE will step through the evaluation.
RECURSE(sequencename, term
n
, term
1
, term
2
)
Example
RECURSE(U,U(N-1)*N,1,2) U1(N)
Stores a factorial-calculating function named U1.
When you enter U1(5), for example, the function
calculates 5! (120).
e
x
e
x
1 –
HP 39gs English.book Page 10 Wednesday, December 7, 2005 11:24 PM