HP 49g Graphing Calculator - Manual (Page 146)

Flags: Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
Example: Find the rational polynomial corresponding to the
following set of roots and poles:
1 , 2 , 3 , - 1
Command: FCOEF{ [ 1 , 2 , 3 , - 1 ] )
Result: ( X - 1 ) ^ 2 / ( X - 3 )
See also: FROOTS
FOURIER
Type: Fimction
Description: Returns the coefficient of a complex Fourier series
expansion. The
PERIOD
variable must be in the current
path, and set to hold L, the period of the input fimction.
Access: Calculus 0(CALQ)
deriv . & integ
Input: Level 1/Argument 2: An expression
Level 2/Argument 1: The number, n, of the coefficient to
return.
Output: The uth Fourier coefficient of the expression.
Flags: Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
Complex mode must be set, that is, flag -103 must be
set.
FROOTS
Type: Command
Description: For a rational polynomial, returns an array of its roots
and poles, with their corresponding multiplicities.
Access: Aiithmetic,
R(ARiTH)
POLYNOMIAI,
Input: A rational polynomial.
Output: An array of the form [Root 1, Multiplicity 1, Root 2,
Multiplicity 2 . . . ]
A negative multiplicity indicates a pole.
Flags: Exact mode must be set (flag -105 clear). Numeric mode
must not be set (flag -03 clear).
Computer Algebra Commands Page 14-23