How do you find the domain and range and determine whether the relation is a function given {(-2.5,1), (-1,-1), (0,1), (-1,1)}?

1 Answer
Shantelle
Aug 2, 2018

Domain: {-2.5, -1, 0}

Range: {-1, 1}

This relation is NOT a function.

Explanation:

The domain is also known as the x-values and the range is the y-values.

Since we know that a coordinate is written in the form (x, y), the x-values are:
{-2.5, -1, 0, -1}

However, when we write a domain or range, we typically put the values from least to greatest and do not repeat numbers. Therefore, the domain is:
{-2.5, -1, 0}

All the y-values are:
{1, -1, 1, 1}

Again, put them from least to greatest and do not repeat numbers:
{-1, 1}

In a function, each x-value can only pair with one y-value (each input has a single output). Since there are two -1s in the x-values pairing with different y-values, this relation is NOT a function.

Hope this helps!

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