Blog Post #2
1. Find an online periodical (newspaper, journal, magazine, etc), not a math periodical, economics is fine, however.
http://www.bbc.com/news/business-29516806
2. Recall the criteria for determining relationships that are functions.
A function is a relationship in which one output is paired with exactly one input.
3. Search the periodical for a relationship that represents a function (in graph, table, or formula format).
4. Explain in words the meaning of this relationship.
Samsung electronics forecasts 60% fall in quarterly profit according to BBC News. Samsung is expecting a drop in profit because of other phone manufacturers such as Apple. Because more people are buying Apple products, the sales of Samsung are decreasing, which ultimately leads the profit to decrease. This is an example of a function because the decrease in sales affects the decrease in profits for the company. For each phone that is sold, there is a dollar amount that is received in profit. Since the sales (x) are declining, the amount that is made is profit (y) is declining as well, ultimately affecting the economy of the company. This function is a mathematical model because the output, total profit, is affected by the input, sales of electronics.
5. Determine whether the function is a linear function.
This is not a linear function because the functions are not constant, and it does not create a straight line.
6. If the function is linear, explain in detail how you know the function is linear (be sure to refer to the average rate of change).
Non- Linear
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).
The function is not linear because the average rate of change is not consistent at every interval. The function both increases and decreases periodically, creating a relationship that is not linear.
8. Determine whether the function is a mathematical model (be sure to use function notation.
This function is a mathematical model because the output, total profit, y, is affected by the input, time, x.
B) 1. Recall the criteria determining relationships that are not functions.
Relationships are not functions when it does not pass the vertical line test and there are multiple outputs for one input.
2. Find an online periodical with a relationship that is not a function.
http://www.nytimes.com/2014/10/04/upshot/jobs-report-highlights-the-wage-growth-puzzle.html?ref=economy&abt=0002&abg=0
3. Explain in words the meaning of this relationship.
Over time, the rate of unemployment has increase and decreased at any given time. As shown in the graph below, there is not a consistent relationship between the points, proving there is a decline in the unemployment rate, but not at a normal rate.
4. Explain in detail how you know the relationship is not a function.
This relationship is not a function because for example, for the 6% unemployment rate, there are two points from September 20014 and December 2007.
paris,
ReplyDeletei like the topic of your first example, and i like how you discussed possible external factors that could be affecting the decline in profit. as far as your explanation about the relationship being a mathematical model, i don't think that the date of the year affects the profit directly, so output is not dependent on input. it would have been nice to see ROC calculations to confirm your explanation about linearity but other than that nice job on the first example.
your second example seems to work as a non function since there are parts of the graph the make a vertical line which breaks the criteria for being a function. good job.
professor little