Which of the graphs below represent functions? Justify your answer.

• Hint (a - c):

  Do all of these graphs have one output value for every input value?

4. For each graph above, state the domain and range.

• Hint 1(d):

  The domain of a graph is its possible $x$-values.

  Domain Answer (d) for graph a:

  All real numbers.

  Hint 2(d):

  The range of a graph is its possible y-values.

  Range Answer (d) for graph a:

  $1\le y\le3$