Functions Lesson

Find f(5) = ?

f(5) means input
is 5, find the output

f(5) = 3(5) + 1
f(5) = 16

​Evaluating Functions

Find f(x) = 10

f(x) = 10 means output
is 10, find input

3x + 1 = 10
3x = 9
x = 3

Multiple Choice

• f(-2) = -1

• f(-2) = -9

• f(-2) = 9

• f(-2) = 0

Multiple Choice

Given f(x) = -4x - 10 and f(x) = 10. Find x

• x = -5
• x = 5
• x = -50
• x = 30

Multiple Choice

Given g(x) =
 4x - 7, find g(-9). 

• g(-9) = 29
• g(-9) = -43

Multiple Choice

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

• 3

• 33

• 51

• -2.66

Multiple Choice

What is the domain of the table?

• {-1, 0, 1, 2, 3}

• {3, 6, 9, 12, 15}

Multiple Choice

What is the range of the function?

• {-2, -1, 0}

• {-5, -3, -1, 3, 5}

Multiple Choice

What is the range of the function?

• {2,3,4,5}

• {8,9,10,11}

Multiple Choice

Find the range for the given domain {-1, 3, 7}

f(x) = 4x-9

• {-5, 3, 19}

• {2, 3, 4}

• {-13, 3, 19}

• {-4, 12, 28}

Multiple Choice

Find the domain for the given range {0, 6, 9}

g(x) = 3(x - 1)

• {1, 3, 4}

• {-3, 15, 24}

• {0, 18, 27}

• {0, 2, 3}

Reasonable Domain is: 0 < x < 8

Reasonable Range is: 80 < y < 440

​

​Reasonable Domain and Range
y = 80 + 45x

Multiple Choice

Gracie's service club is raising money by wrapping presents in the mall. The function f(x) = 3x describes the amount of money, in dollars, the club will earn for wrapping x presents. They only have enough wrapping paper to wrap 1000 presents. Which best represents the reasonable domain and range?

• 1000 ≤ x ≤ 0

  3000 < f(x) < 0

• x ≥ 1000

  f(x) > 3000

• 0 ≤ x ≤ 1000

  0 < f(x) < 3000

• x ≤ 3000

  f(x) <1000

Multiple Choice

Leslie's car travels about 25 miles per gallon of gas. D(x) = 25x represents the # of miles based on x gallons of gas. Her car needs 14 gallons of gas to be full. What is a reasonable domain and range?

• 0 ≤ x ≤ 350

  0 < D(x) < 14

• x < 14

  D(x) ≤ 350

• x > 14

  D(x) > 350

• 0 ≤ x ≤ 14

  0 < D(x) < 350