If is a root
of the polynomial equation
| (1) |
where the s are integers
and satisfies no similar equation of degree
, then is an algebraic
number of degree . If is an algebraic
number and , then it is called an algebraic integer.
Examples of algebraic numbers and their degrees are summarized in the following table.
If, instead of being integers, the s in the above
equation are algebraic numbers , then any root of
| (2) |
is an algebraic number.
If is an algebraic number of degree satisfying the polynomial
equation
| (3) |
then there are other algebraic numbers
, , ... called
the conjugates of . Furthermore, if satisfies any other algebraic equation, then
its conjugates also satisfy the same equation (Conway and Guy 1996).
Any number which is not algebraic is said to be transcendental. The set of algebraic numbers is denoted (Mathematica), or sometimes (Nesterenko 1999),
and is implemented in Mathematica
as Algebraics.
A number can then be tested to see if it is algebraic
using the command Element[x, Algebraics].
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