Search results
Results from the WOW.Com Content Network
The polynomial x 2 + cx + d, where a + b = c and ab = d, can be factorized into (x + a)(x + b).. In mathematics, factorization (or factorisation, see English spelling differences) or factoring consists of writing a number or another mathematical object as a product of several factors, usually smaller or simpler objects of the same kind.
Dividing f(x) by p(x) gives the other factor () = +, so that () = (). Now one can test recursively to find factors of p ( x ) and q ( x ), in this case using the rational root test. It turns out they are both irreducible, so the irreducible factorization of f ( x ) is: [ 5 ]
For polynomials h, g of degree at most n, the exponentiation h q mod g can be done with O(log(q)) polynomial products, using exponentiation by squaring method, that is O(n 2 log(q)) operations in F q using classical methods, or O(nlog(q)log(n) log(log(n))) operations in F q using fast methods.
The Lenstra elliptic-curve factorization or the elliptic-curve factorization method (ECM) is a fast, sub-exponential running time, algorithm for integer factorization, which employs elliptic curves. For general-purpose factoring, ECM is the third-fastest known factoring method.
Now 97 is a non-trivial factor of 8051. Starting values other than x = y = 2 may give the cofactor (83) instead of 97. One extra iteration is shown above to make it clear that y moves twice as fast as x.
If a number x is congruent to 1 modulo a factor of n, then the gcd(x − 1, n) will be divisible by that factor. The idea is to make the exponent a large multiple of p − 1 by making it a number with very many prime factors; generally, we take the product of all prime powers less than some limit B .
An optimal strategy for choosing these polynomials is not known; one simple method is to pick a degree d for a polynomial, consider the expansion of n in base m (allowing digits between −m and m) for a number of different m of order n 1/d, and pick f(x) as the polynomial with the smallest coefficients and g(x) as x − m.
Dixon's method is based on finding a congruence of squares modulo the integer N which is intended to factor. Fermat's factorization method finds such a congruence by selecting random or pseudo-random x values and hoping that the integer x 2 mod N is a perfect square (in the integers):