image

image

Friday, January 17, 2014

My function

Part A



Im ESPN we can find the career statistics of Cristiano Ronaldo and how many goals he has scored since the 2003/2004 season (his first season as a professional soccer player)  until the 2013/2014 season (the current season). We can recall that a function exists when every input has exactly one output. So, the 2003/2004 season was season 1 and the current season is season 11. The data is as follows:

Season 1: 0 goals
Season 2: 9 goals
Season 3: 12 goals
Season 4: 26 goals
Season 5:43 goals
Season 6: 35 goals
Season 7: 33 goals
Season 8: 56 goals
Season 9: 71 goals
Season 10: 62 goals
Season 11: 43 goals (so far)

We can see that each input is assigned to exactly one output, making it a function. We can also observe that this is not a linear function because the rate of change is not constant.

(9-0)/(2-1)= 9

(12-9)/(3-2)= 3

They are not linear because the average rate of change is not constant.

Yes, this is a mathematical model because Cristiano's goals per season improved over the years. The out=put depends on the input. For whatever reason, his performance depended on the years.

y= 5.9455x-0.2182


http://espnfc.com/player/_/id/22774/cristiano-dos-santos-aveiro-ronaldo?cc=5901 




Part B

We can recall that a relationship is not a function when every input does not have exactly one output. An example of a relationship that is not a function is a perfectly inelastic demand curve in economics.



http://www.bized.co.uk/reference/diagrams/Perfectly-Inelastic-Demand-Curve


An inelastic demand curve means that if the price of a good were to increase/decrease, people would still consume the same amount of the product/good.

We know this is not a function because when you plot it on a graph, it does not pass the vertical line test. You cannot determine the specific price from the quantity because a certain quantity has multiple price ranges.











  

7 comments:

  1. Nice work. I like the explanation of part b because you mentioned the vertical line test.

    ReplyDelete
  2. Nice integration of Math and Econ in part b!

    ReplyDelete
  3. I like how you wrote out a table to show how each output matched to one input it was helpful in you explanation.

    ReplyDelete
  4. Not a huge soccer fan but your stats were awesome and your ROC and formula were easy to follow. Your second example was awesome, and I love how you explained in full all the requirements for not being a function as you described it!

    ReplyDelete
  5. "I'm proud to play for Real Madrid because I have fun; when you no longer have fun it's a sign that it's time to leave. For now though, I'm happy here at the greatest club in the world" Cristiano Ronaldo

    ReplyDelete
  6. laith,

    i love your first example! my nephews are heavily into soccer so i am familiar with some of the players. your explanations were accurate and well explained.

    and nice job on the second example. that is clearly a real-life relationship that is not a function.

    professor little

    ReplyDelete