Which statement is correct about relations and functions?
all relations are functions.
all functions are relations.
no relations are functions.
no functions are relations.

All functions are relations.

Step-by-step explanation:

A function in mathematics is a term that describes a relation, such that, any or all the values of input are gives out exactly one value as output.

In other words, it is a relation in which every first element (x-value, input) is not repeatedly used, but once.

For example: a fiction can be presented as A = {(1, 2) (2, 2) (3, 2) (4, 2)}

function

However, a relation on the other hand, is defined as a any set of numbers that are able to be graphed on a coordinate (x, y) plane. A relation can be a function, if and only if, the x- values do not repeat in a given set.

Example of a relation is input ( -1 0 -1 -8 9) output 0 1 2 4 8