関連ワード:  is 3 1 a rational number    is 1 3 a rational number or irrational    is 3 1 2 a rational number    is 3 1 4 a rational number    is 3 √ 1 a rational number    is 3 1 7 a rational number    is 3 1 2 a rational number but not an integer    is 3 1 5 a rational number    is 3 1 8 a rational number    is root 3 1 a rational number