The first set of ordered pairs is not a function. In a function, an input cannot have more than one output. However, one of the inputs in the first set, 3, is paired with two outputs, 1 and 2.

The first set of ordered pairs is not a function. In a function, an input cannot have more than one output. However, one of the inputs in the first set, 3, is paired with two outputs, 1 and 2.