CPM Homework Help : AC Problem 11-63

Which graphs below have a domain of all numbers? Which have a range of all numbers?

Hint 1:

In which graph do all values of $x$ have a corresponding $y$ -value?
Refer to the Math Notes box in Lesson 11.1.4.

Answer 1:

Graphs (a) and (b)

Hint 2:

In which graphs do all values of $y$ have a corresponding $x$ -value?

Answer 2:

Graphs (a) and (c)

Hint 3:

A function can only have one $y$ -value for each $x$ -value.