Blog Post 2
Marie Mikowski

Part 1. Function

http://www.npr.org/blogs/money/2014/04/01/297289442/more-house-less-booze-how-spending-changes-from-age-25-75

A function is a relationship in which there is exactly one output per input. A graph that shows a function must pass the vertical line test and cannot have two of the same y-values. This article has a graph that displays the relationship between age (25-75) and spending (overall and broken into categories). It shows that at the age of 25, spending is at its lowest, peaks in your early 50s, and falls again by the time you reach 75. It is not a linear function because there is no average rate of change, and it is not a straight line. Instead, the graph rises and falls and has constant average rate of change. It is not a mathematical model because spending does not depend solely on age.

Part 2. Not a Function

http://www.npr.org/blogs/money/2013/10/22/239698749/the-most-and-least-lucrative-college-majors-in-2-graphs

A function is a relationship in which there is exactly one output per input. A graph that shows a function must pass the vertical line test and must have no vertical lines. I found an article that provides the most and least lucrative college majors. The article contains a horizontal bar graph that shows the relationship between choice in college major and its corresponding median income. If the major is viewed as the output and the median income viewed as the input, then this relationship does not represent a function because many majors share the same median income (ex. petroleum engineering and health and medical prep programs both come in at $120,000), meaning the graph would create vertical lines, and therefor would not pass the vertical line test, and therefor would not be a function.