Blog number 2. What is your function?

This graph shows the obesity level in percentages, of the American adults aged 20-74. From year 1960 till 2010, the levels of obesity increase at a systematic rate, however at different steepness. The reasons for this may vary. Advancements of fast foods is one of the factor that influenced the increase rate of obesity.  By the end of 2010 we can see that the slope has become less steeper, meaning between 2005 and 2010, people’s healthy habits increased slightly. The relationship between time and obesity rate of adults in America is a function, because for every input of (t) Time in years, there’s a corresponding  output of Y(obesity rate in percentage).  Another reason for this graph to be a function is that that this graph also doesn't pass the vertical test. This graph is not a linear function, because a linear function usually follows a consistent formula, in a consistent manner. This graph doesn't apply to the definition of a linear function, as it had different levels of steepness throughout the years from 1960 to 2010. There is a positive relationship between the time and obesity rate, since it increased throughout all years, however not in a consistent manner. The average rate of change is 0.5. This means that on average the rate of obesity increases 0.5%. This graph can be considered to be a mathematical model, since with time(years), the rate is increasing by 0.5%, which is a positive correlating graph.

Part b:

The following graph displays information about each stock price at different levels at different time points. There is no relationship between time and price because price is not determined by time, which means that in this case, time has the only function to describe each price level at different points in time. As a conclusion price and time are not dependent on each other which makes this graph not a function.