Question

Use the graph to determine the domain and range of the relation, and whether the relation is a function.

a. Domain: x; Range: all real numbers; No, it is not a function.

b. Domain: -8 x 8; Range: all real numbers; Yes, it is a function.

c. Domain: -8 x 8; Range: all real numbers; No, it is not a function.

d. Domain: x; Range: y; Yes, it is a function

Answer 1

A

Explanation:

We can use vertical line test to determine if a relation is a function.

If a vertical line passes the graph at any point only once, then the relation is a function, if there is even 1 line that passes the graph at 2 points, then it is NOT a function.

The domain is the set of allowed x-values of the function. The range is the set of allowed y-values of the function.

• Looking at the graph, we see that there are a lot of vertical lines that cuts the graph two times. Suppose x=3, x=4, x= 5 etc. So it is not a function.
• As for domain, we see that curve swings from x = -8 to x = 8, so the domain is from -8 to 8.
• As for range, we that the curve stretches all the way from negative infinity to positive infinity, so the range is the set of all real numbers.

Correct answer is A