1. RELATIONS & FUNCTIONS
CHAPTER 4

2. Relations A relation is any set of ordered pairs.
The set of input values (or x-coordinate) is called the domain.
The set of output values (or y-coordinates) is called the range.

3. Domain is the set of all x values.
Domain & Range
Domain is the set of all x values.
Range is the set of all
y values.
{(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3)}
Example 1:
Domain-
Range-
D: {1, 2}
R: {1, 2, 3}
*you do not have to repeat numbers in your domain and range answer if they are repeated in the coordinates, but they must be in numerical order

4. Example 2: -8 -6 -4 -2 2 4 6 8 8 6 4 2 -2 -4 -6 -8 -4 -8 -3 6 -4 2 6 8 6 4 2 -2 -4 -6 -8 x y -4 -8 -3 6 -4 2 6
Domain: {-4, -3, 0, 2}
Range: {-8, -4, 6}

5. Graphs
A Relation can be represented by a set of ordered pairs of the form (x,y)
Every equation has solution points (points which satisfy the equation).

6. Ex. Graph y = 2x + 2 x y -2 -1 1 2
Plug the x values into the equation to solve for y
(x values will be given to you)

7. Ex . Graph y = x² - 5 x y -2 -1 1 2

8. Ex . Determine whether the given ordered pairs are solutions of this equation.
(-1, -4) and (7, 5); y = 3x -1