# Determine if a f is a function, surjective or injective.

by George Fong   Last Updated August 25, 2019 10:20 AM - source

How do I determine if these relations are functions, surjectives or injectives?

So here is Question 1:

$$\mathbb{f = \{(a, b) ∈ N^2 × N | a ∈ N^2 , a = (a_1, a_2), b, a_1, a_2 ∈ N, b = a_1a_2\}}$$

And Question 2:

$$\mathbb{f = \{(x, y) ∈ S^2| y = x^2\},\text{ where }S = \{x ∈ R | x ≥ 0\}}$$

I am having a lot of trouble trying to figure these two problems out. The problems themselves are very overbearing and I have no idea where to start.

Tags :

## Union of equivalence classes

Updated November 11, 2017 01:20 AM