HP 38g Graphing Calculator - Manual (Page 57)

Polynomial
Functions
Polynomials are products of constants
(coefficients)
and
variables raised to powers
(terms).
POLYCOEF Polynomial coefficients. Returns the coefficients for the
polynomial with the specified
roots.
POLYCOEF! [roofs] )
Example: to find the polynomial with roots 2,-3, 4, -5:
POLYCOEF ( [ 2 , - 3 , 4 , - 5 ] ) returns [ 1 , 2 , - 2 5 , - 2 6 , 1 2 0 ] ,
representing
x%2з¿-25)¿-2%x+\
20.
POLYEVAL Polynomial evaluation. Evaluates a polynomial with the
specified
coefficients
for the
value
of
x.
POLYEVAL!
[coefficients] , value)
Example: for 25x^—26jc-rl20:
POLYEVAL! [ 1 , 2 , - 2 5 , - 2 5 , 1 2 0 ] , 8 ) returns 3 4 3 2 .
POLYFORM Polynomial form. Creates a polynomial in
variable]
from
expression.
Can express the coefficients as a polynomial in
variable2.
(The coefficients of the coefficients can be expressed
as polynomials in
variables,
etc.)
POLYFORM!
expression, variable 1,.. .,variable-n
)
Example: polyform ! ! x + 1 ) ' ' 2 + 1 , x ) returnsX''2+2* x +2 .
POLYROOT Polynomial roots. Returns the roots for the nth-order polynomial
with the specified
n+l coefficients.
polyroot !
[coefficients]
)
Example: forx“-i-2x*-25x^-26x+120:
POLYROOT! [ 1 , 2 , - 2 5 , - 2 6 , 1 2 0 ] ) returns [ 2 , - 3 , 4 , - 5 ] .
Mathematical Calculations 2-21