Claire Holmberg
Professor Little
Applied Precalc
7 October 2014
Blog Entry 2: Whats
your function?
Part a:
22. A function is a relationship in which one output
is paired with exactly one input.
33. Test scores are a function of family income.
4. This means that as the average family income
increases, test scores rise as well. For every family income interval, there is
one test score, making it a function.
55 & 7.
This relationship is not a linear function because the average rate of
change at every interval on the graph is not the same (or constant), meaning
that it does not create a straight line. The rise of test scores depending on
income is not a constant increase.
88. Test Scores= T, Family Income= I so T = f
(I) is the function notation for this function. This is a mathematical model
because the test score that one receives is dependent on their family’s income.
Consequently, the output value (test score) is dependent on the input value
(family income).
Part b:
11. The criteria for a non-functional relationship
is when there is more than one output value for every input.
33. This relationship reveals that as time (in
years) progresses the time (in hours) of a person running a marathon decreases.
In fact, with the trend seen in this graph, it could be estimated that the time
to run a marathon may drop below 2 hours.
44. This is not a function because at multiple places on the graph, there are multiple output values (times) for certain input values (years). For example, around the year 1950, there were multiple times or records set for running a marathon. It is also evident that this is not a function because the graph does not pass the vertical line test.
44. This is not a function because at multiple places on the graph, there are multiple output values (times) for certain input values (years). For example, around the year 1950, there were multiple times or records set for running a marathon. It is also evident that this is not a function because the graph does not pass the vertical line test.
claire,
ReplyDeletenice job on these examples! i really like your second one and you explained it well.
your first example is good, although, it would have been nice to see ROC calculations when explaining non-linearity. i don't think that your first example is a mathematical model, though. income doesn't affect test scores as someone from a low income household could have a high score and someone from a high income household could have a low test score.
nice reads, though.
professor little