We have proposed an algorithm for determining the sign of the real algebraic numbers, which can be divided into two parts.Both can be the maximum root of their definitional polynomials.

• 摘要对一类特殊的实代数数：可以分成二部分之和，且其中一部分为它定义多项式的最大根，另一部分的相反数也是它定义多项式的最大根进行了研究。