Question

Is the following relation a function
{(-1,1),(0,3),(-1,5),(2,7)}

Answer 1

Answer: This is not a function.

Explanation:

There are two -1.

Answer 2

A function is when the y value doesn't repeat. the x can repeat infinitely but the y can not to be a function.

The y value is the second number in each set and it doesn't repeat so this IS a function