HP 50g Graphing Calculator - Manual (Page 194)

Page 5-17
Polynomials
Polynomials are algebraic expressions consisting of one or more terms
containing decreasing powers of a given variable. For example, ‘X^3+2*X^2-
3*X+2’ is a third-order polynomial in X, while ‘SIN(X)^2-2’ is a second-order
polynomial in SIN(X). A listing of polynomial-related functions in the
ARITHMETIC menu was presented earlier. Some general definitions on
polynomials are provided next. In these definitions A(X), B(X), C(X), P(X), Q(X),
U(X), V(X), etc., are polynomials.
Θ Polynomial fraction: a fraction whose numerator and denominator are
polynomials, say, C(X) = A(X)/B(X)
Θ Roots, or zeros, of a polynomial: values of X for which P(X) = 0
Θ Poles of a fraction: roots of the denominator
Θ Multiplicity of roots or poles: the number of times a root shows up, e.g., P(X)
= (X+1)
2
(X-3) has roots {-1, 3} with multiplicities {2,1}
Θ Cyclotomic polynomial (P
n
(X)): a polynomial of order EULER(n) whose roots
are the primitive n-th roots of unity, e.g., P
2
(X) = X+1, P
4
(X) = X 2 +1
Θ Bézout’s polynomial equation: A(X) U(X) + B(X)V(X) = C(X)
Specific examples of polynomial applications are provided next.
Modular arithmetic with polynomials
The same way that we defined a finite-arithmetic ring for numbers in a previous
section, we can define a finite-arithmetic ring for polynomials with a given
polynomial as modulo. For example, we can write a certain polynomial P(X) as
P(X) = X (mod X
2 ), or another polynomial Q(X) = X + 1 (mod X-2).
A polynomial, P(X) belongs to a finite arithmetic ring of polynomial modulus
M(X), if there exists a third polynomial Q(X), such that (P(X) – Q(X)) is a multiple
of M(X). We then would write: P(X)
≡ Q(X) (mod M(X)). The later expression is
interpreted as “P(X) is congruent to Q(X), modulo M(X)”.
The CHINREM function
CHINREM stands for CHINese REMainder. The operation coded in this
command solves a system of two congruences using the Chinese Remainder
Theorem. This command can be used with polynomials, as well as with integer
Note: Refer to the help facility in the calculator for description and examples
on other modular arithmetic. Many of these functions are applicable to
polynomials. For information on modular arithmetic with polynomials please
refer to a textbook on number theory.