Which of the following is NOT a valid representation of a function?

If A = {1, 2, 3} and B = {a, b}, how many different functions can be defined from A to B?

Which of the following is a bijection (one-to-one correspondence) from set X = {1, 2, 3} to itself?

Given f(x) = x + 2 and g(x) = x^2, what is (g ∘ f)(x)?

What is the inverse of the function f(x) = 2x - 3?

Which of the following sets of ordered pairs represents a function?

If f: A → B is a function, what is the set B called?

A function f(x) is defined as f(x) = x if x is rational and f(x) = -x if x is irrational. What is f(f(√2))?

Consider the function f(x) = |x|. Which statement is true?

Let A = {a, b, c}. How many subsets does A have?