Question

write the following the set builder form
1) set of all positive integers whose cube is odd 2) set of all real numbers which cannot be written as the quotient of two integers

Answer 1

2)
The irrational numbers are the real numbers that are not rational, that is, the real numbers that cannot be expressed as a quotient of two integers. Note that the set of irrational numbers is the complementary of the set of rational numbers
So let A =$\left\{\sqrt{2},\mathrm{\pi },\sqrt[3]{5}..\right\}$

1)
Let the set A = {1,3,5,7,....}