Question

已知由实数组成的集合A满足:若x∈A,则1/1-x∈A.问设A中含有3个元素,且2∈A,求A

Answer 1

由于2∈A,则1/(1-2)∈A,即-1∈A

则1/(1-(-1))∈A,即1/2∈A

所以求得A={2,-1,1/2}