Domain and Range

1
Domain
and
Range
2
Think of a function as a rule that gives a single
output number (y) for every valid input number (x)

• The set of all valid input numbers is the domain
  of the function.
• The set of all valid output numbers is the range
  of the function.

3
Consider a Graph
Y

• X

DOMAIN
4
Consider a Graph
Y

• X

RANGE
5
Consider y x

• Try plugging in some numbers .. What do you
  notice?
• D x gt 0
• if x gt 0, then
• R y gt 0

6
Consider y 2x 4

• Try plugging in some numbers .. What do you
  notice?
• D x R
• if x R, then
• R y R

7
Consider y x2

• Try plugging in some numbers .. What do you
  notice?
• D x R
• if x R, then
• R y gt 0

8
State the Domain and Range
(5,2)

• (-3,-1)

D -3 lt x lt 5
R -1 lt y lt 2
9
Notice
Y
Y
(3,1)
(3,1)

• X

X
D x gt 3 R y gt 1
D x gt 3 R y gt 1
10
State the Domain and Range
Y
X
D x gt -3 R y gt -5

• (-3, -5)

11
State the Domain and Range
Y

• 4

X
D -4 lt x lt 4 R -4 lt y lt 4
12

• Pg 323 1
• 8 Graphs
• Assignment
• to be
• handed in