Functions of the Day

The sets of ordered pairs below represent relations. Which of these sets are also functions?

• I only
• I and IV only
• II and III only
• I, II, and IV

Which relation is a function?

• A
• B
• C
• D

The following relations are written as equations. Which one is not a function?

• x = 4
• y = 4
• x = y + 4
• y = x + 4

Which graph represents a function?

• A
• B
• C
• D

Which table represents a function?

• A
• B
• C
• D

Moira placed $2 in an empty piggy bank, and then added $3 every month. The same day, Nathan placed $5 in an empty piggy bank, and then added $3 every month. The graph below represents their savings.

Based on this graph, which statement is true?

• The amounts in the piggy banks will never be the same.
• At the end of 5 months the amounts in the piggy banks will be equal.
• After the amount in each piggy bank reaches $30, the amounts will continue to be equal.
• The amounts in the piggy banks will always be equal because each piggy bank receives $3 each month.

Jack’s taxi service charges $3.00 for pick up and $2.00 per mile driven. The rates for Taylor’s taxi service are shown in the table below. Suzanne needs a taxi for 10 miles. Which taxi service will cost less, and by how much?

• Jack’s taxi service is less by $6.
• Taylor’s taxi service is less by $9.
• Jack’s taxi service is less by $9.
• Taylor's taxi service is less by $6.

Which of the following equations does not represent a linear relationship between x and y?

• y = 4x
• y = 2x² + 5x
• 5x = 3(y-2)
• 6x - 7y = 13

Which equation is a linear function?

• A
• B
• C
• D

Rhoda and James both sell laptops and earn commission based on the number of laptops sold. In one month, Rhoda earns $2000 in commission for selling 10 laptops and has a base salary of $600. The money James earns for selling laptops in the same month is shown in the graph below. Based on this information, which statement is true?

• Rhoda earns $10 more than James for selling 10 laptops during the month.
• James earns $500 less than Rhoda for selling 10 laptops during the month.
• James earns $50 more in commission than Rhoda for each laptop sold. 
• Rhoda earns $600 more in commission than James for each laptop sold.