Evaluating Functions

g(x) = 5 - 6x
Find g(-5)

• g(-5) = -25

• g(-5) = 6

• g(-5) = 4

• g(-5) = 35

f(x) = 3x² - 11
Find f(-5)

• f(-5) = 64

• f(-5) = -86

• f(-5) = 214

• f(-5) = -7

Let g(x)=9x+24, find g(3).

• 3

• 33

• 51

• -2.66

Evaluate r(3)

• r(3) = 16

• r(3) = 12

• r(3) = 13

• r(3) = 0

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

• y = 2x-3

• f = 2x - 3

• f(x) = 2x-3

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 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.

If f(x) = 2x + 1, find f(1).

• f(1) = 1

• f(1) = 4

• f(1) = 0

• f(1) = 3

Evaluate f(-2) if f(x) = x + 3

• -1

• 1

• 5

• -5