Which of the following is not true?*Every function from the set A to the set B is a relation from the set A to the set B.If f is a function from A to B and (a, b) ∈ f, then f(a) = b, where a is called the pre-image of b under f.Every relation from the set A to the set B is a function from the set A to the set B.If f is a function from A to B and (a, b) ∈ f, then f(a) = b, where b is called the image of a under f.

The statement that is not true is: "Every relation from the set A to the set B is a function from the set A to the set B."

Here's why:

1. Every function from the set A to the set B is indeed a relation from the set A to the set B. This is because a function is a special type of relation where each element in set A is related to exactly one element in set B.

2. If f is a function from A to B and (a, b) ∈ f, then f(a) = b, where a is called the pre-image of b under f. This is true. In a function, the input (a) is often referred to as the pre-image and the output (b) is the image.

3. Every relation from the set A to the set B is a function from the set A to the set B. This is not true. While every function is a relation, not every relation is a function. A relation can have an element in set A related to more than one element in set B, which is not allowed in a function.

4. If f is a function from A to B and (a, b) ∈ f, then f(a) = b, where b is called the image of a under f. This is true