Quiz 9A QR

In mathematics, a function tells us

• how one variable depends on another.

• how an operation, such as multiplication or division, works.

• how inputs and outputs are affected by machines.

The notation r=f(s) implies that values of the variable r depend on

• values of the variable s.

• values of the variable f.

• values of the variables s and f.

The fact that the value of the Dow Jones Industrial Average (DJIA) changes from day to day tells us that

• the DJIA and time are both functions.

• time is a function of the DJIA.

• the DJIA is a function of time.

When you make a graph of a function, values of the independent variable are plotted

• in the range.

• along the horizontal axis.

• along the vertical axis.

When you make a graph of the function z=f(w), which variable is plotted on the vertical axis?

• w

• z

• f

The values taken on by the dependent variable in a function belong to the function’s

• domain.

• range.

• limits.

Consider a function that describes how a particular car’s gas mileage depends on its speed. An appropriate domain for this function would be

• 0 to 100 miles per hour.

• 0 to 50 miles per gallon.

• times from 0 to 10 minutes.

The input values for a function come from the function’s

• range.

• domain.

• coordinate plane.

All of the following are functions of time. Which one would you expect to be closest to being a periodic function of time?

• the price of gasoline

• the population of the United States

• the volume of traffic on an urban freeway

Suppose that two groups of scientists have created mathematical models that they are using to predict future global warming. In general, which model would you expect to be more trustworthy?

• the one with more functions

• the one that predicts past temperature values that are closer to actual past temperature values

• the one that extends further into the future with its predictions