Lesson Function Notation and Evaluating Functions

Evaluate f(x) = x² for x = -8

• 64

• -64

• -16

• 16

Evaluate f(x)=-2x+13   for f(10)

• -7
• 1
• -8
• 7

What is the definition of function?

• Has inputs and outputs
• Every input has only ONE output
• Inputs have different outputs every time
• x-values and y-values

How would you write y = 2x - 3 in function notation?

• y = 2x-3

• f = 2x - 3

• f(x) = 2x-3

How do you read f(x)?

• f x

• f of x

• f parenthesis x

• f with an x inside parenthesis

If a question asks you to find f(2), what does that mean?

• Let x = 2

• Let y = 2

If f(x) = 2x + 1, what would be your first step to find f(1)?

• Plug a 1 in for all the x's

• Set the function equal to 1

• Only plug a 1 into the left side

• Only plug a 1 into the right side

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

If I know that f(2) = 4, what is another way I can write my answer?

• 2,4

• (2, 4)

• That is the only way to write it.

• -9

• -4

• 1

• 7

• 12