Question

Write the following in set-builder form:-i) Set of all positive integers whose cube is odd ii) Set of all real numbers which cannot be written as the quotient of two integer

Answer 1

i) {x : x is a positive integer, $x^{3}$ is odd}
                                
ii) {x : x is an irrational number}

However, there are many ways in which a set can be expressed in the set-builder form. These are just two of them.