What's Your Function?

A)  http://www.economist.com/blogs/dailychart/2011/11/global-house-prices
This article in 'The Economist' discusses how the international housing market is picking up quickly, with great gains even in just the past year. It uses the markets of Britain, America, and Japan as its case studies, and compares the years from 1975 to 2013. In the case of this graph, the input is the year and the output is how good the housing market was for each country.

This function is linear because the pickup in the housing market for each country passes the VLT. The function is a mathematical model because the output is dependent on the input. As the years pass, the output (state of the nation's housing market) either becomes stronger or weaker. F(year)= house price index.

B)  http://www.accuweather.com/en/us/atlanta-ga/30303/weather-forecast/348181?partner=Googleonex
Jan. 17th: 11 mph
11 mph
10 mph
11 mph
Jan. 18th: 11 mph
10 mph
7 mph
8 mph
Above is Atlanta's wind forecast for the 17th and 18th. This relationship between date and speed of wind is not a function because there cannot be more than one wind speed during the whole day. This is saying that on these dates, the wind speeds were varying in the same city.

Blog Post 2

Part A

http://www.weather.com/weather/wxclimatology/monthly/USDC0001

These are the yearly average from the temperature in Washington DC. The statistics show that the overall temperature has dropped since 2009.

This is the relationship between the weather and the year has no correlation. The weather is the F and the year is the X. This is a linear function because it has a constant rate of change over each year that the data was recorded. This function is not a mathematical model because the output is not dependent on the input.

Part B

 http://www.baseball-reference.com/players/r/rodrial01.shtml

This article is on one of the greatest baseball players of all time and his stats. They show his stats from when he first started in the MLB to now in his veteran career. The article argues that MLB younger hitters do better than older hitters. This is not a function because age has nothing to do with how good a batter is. The age is not dependent on how well the hitters hit. Young players hit just as well as older players.

What's Your Function? Blog Post 2

Part a:

http://www.theatlantic.com/health/archive/2014/01/how-much-do-we-sleep-americans-dont-know/283148/call the criteria for determining relationships that are functions.

This article shows the relationship of how many hours of sleep US citizens get from the years 1942, 1990, 2001, 2004, and 2013.  It shows the rise in recent years of people getting less sleep per night.  The function is not linear because the numbers vary and there is no average rate of change that can be calculated.  For example in the category of Five hours of sleep or less, the percentages varied from 3, 14, 16, 14 and 14 in their corresponding years.  The output is not dependent on the input, or the amount of sleep is not dependent on what year the data was taken, therefore it is not a mathematical model.  

Part b:

http://www.theatlantic.com/business/archive/2014/01/the-growth-of-college-grads-in-dead-end-jobs-in-2-graphs/283137/

This article is about recent college graduates and the jobs that they have which do not require a degree, essentially making them underemployed for their education level.

The first graph is titled Underemployment Rates for College Graduates.  This shows the relationship between recent college graduates and their unemployment percentage from 1990 to 2012.  The relationship is not a function because the output is not dependent on the input; the numerical year does not have an effect on the percent of the college graduates underemployed.  

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. 

Blog #2

Part A
https://www.google.com/finance?q=INDEXNASDAQ:.IXIC&sa=X&ei=UsXZUqLIMLLFsATSsoGgAg&ved=0CCoQ2AEwAA

This graph shows the relationships between rates of NASDAQ exchange and time from January 2013 to today, January 2014. The outputs are the amount of dollars and inputs are dates.  From the graph, there is a tendency that today's average market rates seems like increased. The average of the market rates is ((4214-3012) /(2014-2013) = 1202) 1202 dollars per year, and it increases. It passes VTL, therefore it is a function. However, if you look at carefully, there are many changes between days. Therefore, this is  not a mathematical model since market rates will change day by day depends on economical situation.

Part B:
Nonfunctional means that when you look at some amount of data or line graph and if there are the same amount of numbers or the same points on the vertical line, it considers as a nonfunctional.
http://ahundredyearsago.com/2012/02/06/average-height-for-males-and-females-in-1912-and-2012/
This article is about average height and age of year of male and female. According to this line graph, the outputs are heights and inputs are age of year. From the graph it can be recognized that their heights stop at a certain age which is 21. Based on the nonfunction definition,  the height stops at age of 21, therefore it doesn't grow constantly. Therefore, this is an example of the nonfunction.

What is your function? Blog Post #2 by David Fernando Varela Alvarado

So.... What is your function?

Part A  

The graph shown by this article exposes several sets of data that represent the billions of dollars spent on research and development by different countries. The graph displays a relatively constant research and development expenditures for Japan, Germany and U.K. Furthermore, China and US are making considerable changes. As we can appreciate china has made large investments in new technologies and it is expected to make larger investments in comparison to the U.S. The relationship of these graphs can be considered by a linear function because these increases in research and development may be dictated by a specific budget and also specific budgets increases planned for future years. Also it is a function because passes the Vertical Line test, which states that, in this case, for every year, there can only be one level of expenditures. Moreover, I can conclude that this can be a mathematical model because governments and companies use formulas in order to determine how much resources they can use depending on factors such as revenues and costs that might directly affect the resources available for research and development.

http://online.wsj.com/news/articles/SB10001424052702303819704579320544231396168

Part B.

The following graph is taken from the stock prices of Apple. There is a relationship between time and price given that for every factor of time, there is a specific price. Having said all that, I can say that the following graph is not a function because the output is not a function of time. Time does not determine the price of the stock. And even if we consider time as an accounting period where the company issues it’s financial statements periodically, we cannot attribute a function to determine these price levels, which would make everyone have an advantage in determining stock prices.

http://www.google.com/finance?q=Apple&ei=B-_ZUpjID43U6QH-ZQ

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Blog Post #2

Part A:

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_04_23.html

4.     Explain in words the meaning of this relationship.

This is the relationship between miles that can be driven to the amount of gas put into a car that is measured as miles per gallon (fuel efficiency) of light duty cars over the years.

  

5.     Determine whether the function is a linear function. 

This would not be a linear function.

7.     If the function is not linear, explain in detail how you know it is not linear (be sure to refer to the average rate of change).

This function is not a linear function because it does not have a constant rate of change over each year that the data was recorded.

8.     Determine whether the function is a mathematical model (be sure to use function notation.

Yes this is a mathematical model because it measures fuel efficiency which is the relationship of how much gas can be put into a car and that directly effects how many miles that you can drive.

Part B:

1.     Recall the criteria determining relationships that are not function.

2.     Find an online periodical with a relationship that is not a function.

http://espn.go.com/nba/statistics/player/_/stat/assists/sort/assistTurnoverRatio

3.     Explain in words the meaning of this relationship.

The article focuses on the current leaders of assist to turnovers in the NBA. The relationship involves how many assists NBA players have so far in the season per turnover that they commit.

4.     Explain in detail how you know the relationship is not a function.

This would not be considered a function because the assists do not directly impact the turnovers it is just a comparison as well as the turnovers do not directly affect the assists. You can have 10 turnovers but it does not affect your assists.

Part C:

1.     After completing your blog entry, thoughtfully and critically comment on the posts of members in your blog group.