Unit 5, Lesson 2# Formal Definition of a Function

EngageNY 45 min(s)

The correspondence is often given as a rule (e.g., the output is a number found by substituting an input number into the variable of a one-variable expression and evaluating). Students develop here their intuitive definition of a function as a rule that assigns to each element of one set of objects one, and only one, element from a second set of objects. Shown below is the table from Example of the last lesson and another table of values for the alleged motion of a second moving object. The table on the right gives two completely different distances for the stone after 1 second.