Interpreting Functions Review

Is this table a function?  Why?

• Yes, because none of the inputs repeat.
• Yes, because the inputs repeat but have the same output.
• No, because the inputs repeat and have different outputs.

Is the graph a function?  Why?

• Yes, it's a perfect circle.
• No, if I draw a vertical line, it crosses twice.
• Yes - if I draw a vertical line, it crosses only once.
• No - it's a perfect circle.

Is this table a function?  Explain.

• Yes, because none of the inputs repeat.
• Yes, because the inputs repeat but have the same output
• No because the inputs repeat
• No because the inputs repeat and have different outputs

What is the domain of this function? 

• All real numbers (because graphs never end)
• All the numbers between -2 and 2
• All the numbers except between -2 and 2
• All real numbers above -2

What is the domain of this function?

• All real numbers
• All real number bigger than 0
• All real number bigger than or equal to 0
• All real numbers less than 0

Consider the function f(x)=9x+5.  Find f(7).

• 102
• 68
• 7
• 21

Consider the function k(x)=x/5-3.  Find k(-20).

• -20
• 1
• -7
• -1

Derek works at Subway making $9.25 an hour.  The function d(x)=9.25x tells us how much money Derek makes after x hours of working.  What is the meaning of d(4)=37?

• After 4 hours of work, Derek makes $37.
• Derek needs $4 more to have $37 total.
• After working for 4 days, Derek makes $37 total.
• After 4 hours of work, Derek now makes $37 an hour instead of $9.25.

Ms. Brackemyer is collecting pencils.  The function p(x)=5x+12 tells us the total amount of pencils Ms. Brackemyer has after collecting for x number of days.  What is the meaning of p(8)=52?

• Ms. Brackemyer starts with 8 pencils and ends with 52.
• After 8 days, Ms. Brackemyer has 52 pencils.
• Ms. Brackemyer starts with 52 pencils and gets 4 more every day.
• Every day, Ms. Brackemyer gets 4 new pencils until she has 52.

A company is selling bubble gum.  The function g(x)=3x+4 tells the company how much to charge if someone buys x packages of bubble gum.  Find g(8) and tell what it means within the context of the problem.

• g(8)=8.  This means that after 8 packages of gum, the company makes $8.
• g(8)=42.  This means that 8 packages of gum costs $42.
• g(8)=28.  This means that 8 packages of gum costs $28.
• g(8)=24.  This means that 8 packages of gum costs $24.