log #2 Seth Brennock
Part A
1. Find an online periodical, not a math periodical, economics is fine, however.
- New car sales by year
- http://www.forbes.com/sites/jimhenry/2012/01/20/average-car-in-the-u-s-now-over-10-years-old-a-record/
2. Recall the criteria for determining relationships that are functions.
- Yes this is a function because the equation only has one output for every input.
- Passes the vertical line test.
3. Search the periodical for a relationship that represents a function (in graph, table, or formula format)
Year- x # of new cars sold-y
2007 16.2
2008 13.4
2009 10.4
2010 11.6
2011 12.8
4. Explain in words the meaning of this relationship.
- This table represents the number of new cars sold each year between 2007-2011.
5.
-No, this function is not a linear function. There is not a consistent slope.
6. Not linear
7. The slope is inconsistent- shown with slope formula y2-y1/x2-x1 The average rate of changes for each.
8. Determine whether the function is a mathematical model
- This is a mathematical function because the # of new cars sold is dependent on the year.
- Function notation: amount of #new cars sold=f(year)
Part B
1. Recall the criteria determining relationships that are not functions
-Multiple Inputs result in the same output
-Fails the vertical line test
2. Find an online periodical with a relationship that is not a function.
-http://www.rush.edu/health-wellness/quick-guides/what-healthy-weight
3. Explain the meaning of this relationship.
- The chart shows the average weights for certain heights.
4. Explain in detail how you know this relationship is not a function.
- This isnt a function because at each height there are multiple weights. For it to be a function there would have to be one singular output for each input.
image
It is apparent and obvious that the each year the car sales increase. It is interesting to see that this relationship is a function.
ReplyDeleteSince this does pass the vertical line test, maybe show the work to prove the average rate of change. This would help the readers see your main point, even though it is obvious it is a linear function.
Good job finding an article that relates to this section.
For Part B, you could definitely elaborate more on how it is not a function and list main reasons why.
hi, seth,
ReplyDeletenice job on your first example. your explanations are pretty clear, but i agree with paris that it would have been nice to see ROC calculations to confirm non-linearitly. also, i am entirely convinced that year determines how many cars will be sold. i don't think that the function is a mathematical model.
for your second example, from just looking at the chart i could rationalize that it represents several different relationships that are functions, hence, you should be specific about which is the input and which is the output.
professor little