Linear, Quadratic, and Exponential Situations

A machine salesperson earns a base salary of $40,000 plus a commission of $30 for every machine (x) he sells.

• Linear; y = 30x + 40000

• Linear; y = 40000x + 30

• Exponential; y = 40000(1.30)^x

• Exponential; y = 40000(30)^x

Which situation could be modeled by using a linear function?

• a bank account balance that grows at a rate of 5% per year, compounded annually

• a population of bacteria that doubles every 4.5 hours

• the cost of cell phone service that charges a base amount plus 20 cents per minute

• the concentration of medicine in a person’s body that

  decays by a factor of one-third every hour

Which situation is not a linear function?

• A gym charges a membership fee of $10.00 down and $10.00 per month.

• A cab company charges $2.50 initially and $3.00 per mile.

• A restaurant employee earns $12.50 per hour.

• A $12,000 car depreciates 15% per year.

What function model best represents the data in the table?

• linear

• exponential

• quadratic

One characteristic of all linear functions is that they change by

• equal factors over equal intervals

• unequal factors over equal intervals

• equal differences over equal intervals

• unequal differences over equal intervals

Which of the three situations given below is best modeled by an exponential function? I. A bacteria culture doubles in size every day. II. A plant grows by 1 inch every 4 days. III. The population of a town declines by 5% every 3 years.

• I, only

• II, only

• I and II

• I and III

r(-2) = ?

• r(-2) = -12

• r(-2) = -8

• r(-2) = -4

• r(-2) = -2

Identify the function family.

• Linear

• Exponential

• Quadratic

• Constant

Which situation is not a linear function?

• A gym charges a membership fee of $10.00 down and $10.00 per month.

• A cab company charges $2.50 initially and $3.00 per mile.

• A restaurant employee earns $12.50 per hour.

• A $12,000 car depreciates 15% per year.

Ian is saving up to buy a new baseball glove. Every month he puts $10 into a jar. Which type of function best models the total amount of money in the jar after a given number of months?

• linear

• exponential

• quadratic

• square root