Function Notation

Table of Contents 6: Warm-Up, Guided Practice 7: What is Function Notation?

Warm-Up Poll Are the following points solutions to the equation? 1. 3x – 2y = 11 2. y = -2x - 3 Point: (5, 2) Point: (-2, 1) 3. x – 7y = 3 4. y = 3x - 1 Point: (-4, -1) Point: (3, 5)

Warm-Up Are the following points solutions to the equation? 1. 3x – 2y = 11 2. y = -2x - 3 Point: (5, 2) Point: (-2, 1) 3. x – 7y = 3 4. y = 3x - 1 Point: (-4, -1) Point: (3, 5) True True True False

Learning Intention/Success Criteria LI: We are learning to solve equations while using function notation SC: I know how to -use function notation to evaluate functions -use function notation to solve problems in tables -use function notation to solve problems in graphs

EQ: What is Function Notation? 5/19/20195/19/2019

Function Notation The notation used to describe a function It’s a fancy way of saying “y =“ Used to evaluate functions In Context What the answer means in terms of the problem Table Data arranged in rows and columns

Example 1: Evaluate f(x) = 3x – 8, when x is 2 f(x) = 3x – 8 f(2) = 3(2) – 8 f(2) = 6 – 8 f(2) = - 2 When x is 2, f(x) is -2. This makes the point (2, -2)

Guided Practice 1 and Poll Evaluate f(x) = 2x + 10, when x = -7 A] f(-7) = - 4 B] f(-7) = 4 C] f(-7) = -140 D] f(-7) = -24

Guided Practice 1 Evaluate f(x) = 2x + 10, when x = -7 f(x) = 2x +10 = -14 + 10 = -4

Guided Practice 2 and Poll Evaluate g(x) = x + 9, when x = 5 A] g(5) = 4 B] g(5) = 14 C] g(5) = 45 D] g(5) = -4

Guided Practice 2 Evaluate g(x) = x + 9, when x = 5 f(x) = x + 9 = 5 + 9 = 14

Guided Practice 3 and Poll Evaluate h(x) = 2x – 6, when x = 0 A] h(0) = 6 B] h(0) = -6 C] h(0) = 0 D] h(0) = 2

Guided Practice 3 Evaluate f(x) = 2x – 6, when x = 0 f(x) = 2x - 6 = 0 - 6 = -6

Example 2: Suppose M(t) represents the amount of money in your bank account each week. You start with $6 in your account and add $2 each week, where t is the number of weeks.

Fill in the table defined by the function: M(t) = 2t + 6 1 2 3 4 5 6 M(t) 8 10 12 14 16 18 M(t) = 2t + 6 M(1) = 2(1) + 6 = 2 + 6 M(t) = 2t + 6 = 8 M(3) = 2(3) + 6 M(t) = 2t + 6 = 6 + 6 M(2) = 2(2) + 6 = 12 = 4 + 6 = 10

What is the value of M(4)? M(4) = 14 What does M(4) represent in context? M(4) represents the amount of money in your account, after 4 weeks, which is $14. For which values of t does M(t) = 10? M(t) = 10 when t = 2.

Reflection How do you answer a question when it asks for the context of something?

Quiz Evaluate the following expressions given the function 1. g(x) = -3x + 1 when x = 10 2. f(x) = x2 + 7 when f = 3 3. j(x) = 2x + 9 when j = 7 Translate the following statements into coordinate pairs: 4. f(-1) = 1 5. h(2) = 7 6. g(1) = -1

Homework Things you should be doing right now… Working on your homework Working on your MiMOW Checking your work on the class website Listening to music if you have head phones and no one else can hear your music