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Friday, January 17, 2014

What's my Function?

A) I looked up to see what the popularity of facebook was. The amount of users on facebook has increased over the past years. Until 2008, facebook "only" had 100 000 000 users, which today is over 1 100 000 000. This is a function, with only one output per input, and the amount of users is dependent on the time (for multiple reasons such as marketing, globalization etc.) It is not a linear function, since the Average rate of change is not the same:

Y2- Y1 / X2 - X1 = 0 - 8000000 / 2005-2004 = 8000000
Y2 - Y1 / X2 - X1 = 100 000 000 - 50 000 000 / 2008 - 2007 = 50 000 000 

It is a mathematical model, where f(x)=y, where x is time and y is number of users. 

B) The table I found that represents a mathematical model but not a function is the fastest someone's run a mile. This is not a function since the running time is independent of the year It's not actually the difference between year "x" and year "y" that sets the records. 

5 comments:

  1. This comment has been removed by the author.

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  2. What was the fastest time?

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  3. Great job organizing your stuff!

    Im also glad you touched on the importance of dependency in mathematical models and managed to use a mathematical model that wasn't a function.

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  4. That's so interesting how the math is applied to Facebook!

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  5. karolina,

    yay! i really love your first example. you used a social media example explain math in a social media format. love it! your explanations for why it is a function and why it is not linear were spot on! however, i do not think that this example constitutes a mathematical model. users are not entirely dependent on year. you could argue that increased popularity happens over the years, but still popularity could go down next year and then it wouldn't really fit the definition for mathematical model.

    for your second example, running time being independent of year is not a valid reason for why a relationship is not a function.

    professor little

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