Recognizing functions from graphs

The  exercise appears under the 8th Grade Math Mission. This exercise begins to recognize what makes a relation a function.

Types of Problems
There are two types of problems in this exercise:


 * 1) Determine if word problem represents a function: This problem describes a situation in context. The student is expected to determine if the problem describes a situation that could be modeled with a function.Rf2-1.png
 * 2) Determine if drawing is a function of either variable: This problem has provides the graph of a relation. The student is asked to determine if the graph is x as a function of y, y as a function x, neither, or both.Rf2-2.png

Strategies
Knowledge of function notations and the various forms of functions are an advantage when trying to complete this exercise.
 * 1) A function must be assigned a unique output for any input.
 * 2) For graphical situations, a graph is a function of y in terms of x if it passes the vertical line test. It is a function of x in terms of y if it passes the horizontal line test.

Real-life applications

 * 1) Functions are the building blocks of much of the calculus.
 * 2) Functions can be used to model many aspects of business and science.