How would I prove that f(x) = [x] is surjective, where [x] denotes the bracket function
I know how to prove that something is surjective, but I'm stuck on this particular example
In proofs of surjection, knowing the domain and codomain is essential. For example, f(x) = [x] is not surjective if f is considered from to , nor when it is considered from to . So I'll assume that .
We need to prove that for every there is an such that [x] = n. Can you find several such x for n = 3?