An Etymological Dictionary of Astronomy and Astrophysics

A number, → real or → complex, that is a → root of a → non-zero polynomial equation
whose → coefficients are all → rational. For example, the root x of the polynomial x² - 2x + 1 = 0 is an algebraic number, because the polynomial is non-zero and the coefficients are rational numbers. The imaginary number i is algebraic, because it is the solution to x² + 1 = 0.

See also: → algebraic; → number.