Question

For the following relation, give the domain and range, and indicate whether it is a function.{(3, 5), (1, 4), (8, 6), (9, 2)}Domain: {Range: {Is it a function?Select an answerYesNo

Answer 1

ANSWERS

• Domain: {1, 3, 8, 9}

,

• Range: {2, 4, 5, 6}

,

• Yes, it is a function.

EXPLANATION

The domain is the set of all x-values for which the relation has a y-value. In this case, the relation is given as a set of points, so the domain is the set of all the x-coordinates. Note that this set has to be expressed by ordering the values from least to greatest, not in order of appearance in the relation.

Hence, the domain is {1, 3, 8, 9}.

The range is the set of all the y-values the relation can take. In this case, the range is the set of all the y-coordinates of the points in the relation.

Hence, the range is {2, 4, 5, 6}.

To determine if a relation is a function, we have to see if there are any points with the same x-coordinate but different y-coordinate. If there is at least one pair of points with the same x-coordinate, then the relation is not a function.

As we can observe, there are four different x-values for four different y-values. Therefore, this relation is a function.