options: Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line.

Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change.

Understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output. (Function notation is not required in Grade 8.)
problem_activity: At a local bank, when you open an account, you provide certain information that is stored in the bank's records. The table below shows the names and mailing zip codes of some of the bank's customers.
{"table": [{"_attributes": {"align": "center", "class": ["table", "table-bordered"], "style": "table-layout:Fixed; width:50%"}, "tbody": [{"tr": [{"td": [{"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"_value": "Customer Name"}]}, {"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"_value": "Zip Code"}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "_value": "Tyler Jackson"}, {"_attributes": {"style": "text-align:center"}, "_value": "70114"}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "_value": "Justine Goodman"}, {"_attributes": {"style": "text-align:center"}, "_value": "12084"}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "_value": "Tristan Manuel"}, {"_attributes": {"style": "text-align:center"}, "_value": "30311"}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "_value": "Vanera Caro"}, {"_attributes": {"style": "text-align:center"}, "_value": "30311"}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "_value": "Mia Lee"}, {"_attributes": {"style": "text-align:center"}, "_value": "20815"}]}]}]}]}
a.   Suppose
F
is the rule that takes a customer's name and provides their mailing zip code. According to the information in this table, is
F
a function? Explain your reasoning.
b.   Suppose
G
is the rule that takes a customer's mailing zip code and provides their name. According to the information in this table, is
G
a function? Explain your reasoning.
c.   If the bank is looking for a way to identify specific customers, why would using their zip code
not
be a good way to do this? What other input might the bank use instead?


correct_option_index: 2