2a+Introduction+to+functions,+Domain+and+Range,+tests+for+a+function

Helpful links: http://sk19math.blogspot.com/2007/04/functions-introduction.html http://iws.ccccd.edu/yjlangford/Math%200310/Math%200310%20Lecture%20Notes/2008%20(Carson)%20PDF%20form/4.7%20Introduction%20to%20Functions%20and%20Function%20Notation.pdf

Example Problems: 1) Given set - {(5,10),(10,10),(15,10)} Domain (x values) - (5, 10, 15) Range (y values) - (10) Is this a function? Yes, because there is only one x (input) for every y (output). As you can see below, the line passes the vertical line test showing that it doesn't hit the vertical line more then once throughout the plots.

2) Given set - {(1,2),(1,3),(2,4)} Domain (x values) - (1, 2) Range (y values) - (2, 3, 4) Is this a function? No, because there is two different outputs (2 and 3) for the same input (1). As you can see below, the line fails the vertical line test as it hits the vertical line twice in the same x value.

James