Functions

Question 1

What does it mean for a function to be injective?

Answer 1

Given two sets A and B, Ax and only point to one Bx. However for any given Bx there doesn’t necessarily have to be an Ax pointing to it.

Question 2

What does it mean for a function to be surjective?

Answer 2

Given two sets A and B, every Bx must have atleast one Ax (Possibly more)

Question 3

What does it mean for a function to be bijective?

Answer 3

Given two sets A and B, every Ax must point to 1, and only 1, Bx and every Bx must have 1, and only 1, Ax pointing to it. A perfect pairing.