idempotent

1.The necessary and sufficient conditions of similarity of two idempotent matrices are proved, the idempotency of linear combinations of two idempotent matrices is discussed.

摘要证明数域上两个同阶阵相似充要条件是它们有相同秩；给阵相似标准型；讨论两个阵线性组合仍是阵充要条件。