HP 40gs - Page 235

Computer Algebra System (CAS) 14-53
FACTORMOD Factors a polynomial in Z/pZ[X], providing that p ≤ 97,
p is prime and the order of the multiple factors is less than
the modulo.
Example
Typing:
FACTORMOD(–(3X
3
– 5X
2
+ 5X – 4))
gives:
GCDMOD Calculates the GCD of the two polynomials in Z/pZ[X].
Example
Typing:
GCDMOD(2X
2
+ 5, 5X
2
+ 2X – 3)
gives:
INVMOD Calculates the inverse of an integer in Z/pZ.
Example
Typing:
INVMOD(5)
gives:
–5
since 5 · –5 = –25 = 1 (mod 13).
MODSTO Sets the value of the MODULO variable p.
Example
Typing:
MODSTO(11)
sets the value of p to 11.
3x 5–()x
2
6+()⋅()–
6x 1–()–
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