Function Notation, Graphs and Story Problems

Is this a function?

• Yes

• No

• Let me ask my dog...

• Why are there letters in math?

Which set of values is a function?

• (9,5) (10,5) (9,-5) (10,-5)

• (3,4) (4,-3) (7,4) (3, 8)

• (6,-5) (7, -3) (8, -1) (9, 1)

• (2, -2) (5, 9) (5, -7) (1, 4)

Which set of values is not a function?

• (9,5) (10,5) (4,-5) (8,-5)

• (3,4) (4,-3) (7,4) (3, 8)

• (6,-5) (7, -3) (8, -1) (9, 1)

• (2, -2) (5, 9) (-5, -7) (1, 4)

If f(x) = 2x+1, what would the function look like once you substitute in a 1 to find f(1)?

• f(x) = 21+1

• f(1) = 2 (1) + 1

• f(1) = 2x (1) + 1

For the function f(x) = -3x + 3 find f(0).

• 0

• -3

• 3

• -1

Solve for f(5):
f(5) = -x + 4

• 9 

• 1

• -1

• -9

Is this a function or not?

• Function

• Not a Function

If f(x) = -3x - 8, find f(-1).

• f(-1) = 5

• f(-1) = -5

• f(-1) = -12

• f(-1) = -10

• 1.5

• 5

• 3

• 8

• x=2

• x=6

• x=3

• Not possible