Recognizing functions from tables

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 three types of problems in this exercise:


 * 1) Use the vertical or horizontal line test: This problem has a graph and the student is expected to look at the graph and determine if one variable is a function of the other.Rf1.png
 * 2) Solve to see if an equation is a function: This problem provides an equation and asks the student to state whether or not it represents a function.Rf2.png
 * 3) See if chart is a function: This problem provides a chart and asks the student to determine if the chart represents a function.Rf3.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.
 * 3) In a chart, a function will not have repeated x-values going to different y-values.
 * 4) In a rule, a function can be isolated for y.

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.