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# Cubic numbers

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(Redirected from Cubic integers)

*Not to be confused with cubes (also called***perfect cubes**), integers which are the third power of an integer.

**Cubic numbers** are the roots of the cubic equation

where

Although **cubic numbers** do include quadratic numbers and rational numbers as subsets, **cubic numbers** usually refer to numbers for which the minimal polynomial has degree 3.

## Contents

## Cubic integers

**Cubic integers** are the zeros of the monic cubic polynomial

where

## Examples

### Roots of x^3 - x^2 - 1

A092526 Decimal expansion of (2/3)*cos( (1/3)*arccos(29/2) ) + 1/3. (Real root of .)

- 1.46557123187676...

## Cubic numbers among the algebraic numbers

- Rational numbers: algebraic numbers of degree one (rational integers:
^{[1]}algebraic integers of degree one) - Quadratic numbers: algebraic numbers of degree two (quadratic integers: algebraic integers of degree two)
- Cubic numbers: algebraic numbers of degree three (cubic integers: algebraic integers of degree three)
- Quartic numbers: algebraic numbers of degree four (quartic integers: algebraic integers of degree four)
- Quintic numbers: algebraic numbers of degree five (quintic integers: algebraic integers of degree five)
- ...

## See also

## Notes

- ↑ The rational integers are the common integers designated by .