Chapter 3.1 – 3.3 Relations & Functions Alg. 2 Notes Name:__________________ Date:________________ Assignment:

Chapter 3.1 – 3.3 Relations & Functions

Alg. 2 NotesName:__________________

Date:________________Assignment:

Domain and Range

• Domain = the set of all x-values.• Range = the set of all y-values.• List the domain and range of the relation

{(a,1), (b,2), (c,3), (e,2)}

D:

R:

Set Builder Notation:{x I x 3}

Example: Use the set {1,2,3,…,10} Find {x I x ≥ 7}

Example: write the following using set builder notation { 4,5,6}

Set Builder Notation:

Example: Use the set {0,2,4,6,8} Find {x I 2 < x ≤ 8}

Example: write the following using set builder notation { 0,1,2,3,4,….}

Cartesian Coordinate System

Checking Solutions: Plug in!

• Determine if (-1,4), (0,6) are solutions to y = -2x + 5

Graphing Equations:

𝑦=𝑥2 - 2

Meet the parabola guy! Get to know him now. He will be your friend by the

end of the year

Which ones are Functions?

a)(3, -9), (-2, 8), (-3, -9)

b)(5, 8), (-2, 3), (3, 10), (-2, -6)

d)

c)

Function Notation:

Example : Evaluate f(-2) for f(x) = -2x2 – 1

Finding Domain (1st degree)

State what values are acceptable

When are values not acceptable?

If they make the denominator = 0 or a Square root negative like…

2

3)(

x

xxf

Domain = {x | x }

Sometimes we define domain by what it can’t be!

Domain = {x | x }

Practice:

1) Given f(x) = 2x + 6 a)What is the domain?

b)Find f(3)

2) Given

a) What is the domain

b) Find h(-6)

5

1)(

x

xh

Give the Domain and Range: