Download functions

What’s a Function?
• First of all what does the
word relation mean to you?
• A relation in math is a
group of ordered pairs,
just like your aunt and
uncle.
What’s a Function?
• A relation in math is a
group of ordered pairs.
• A function is a relation in
which no two ordered
pairs have the same
x-value.
What’s a Function?
• A function is a relation in
which no two ordered
pairs have the same
x-value.
• (3,2) , (4,5) , (6,-1) , (0,2)
is a function because all
What’s NOT a Function?
• A function is a relation in
which no two ordered
pairs have the same
x-value.
• (-3,2) , (4,5) , (6,-1) , (4,2)
is NOT a function.
What’s a Function?
What’s NOT a Function?
What’s a Function
Input
Output
What’s a Function
x
The value of y
depends on x
Output
y
What’s a Function
1
Output
5
What’s a Function
2
Output
?
Function Notation
• (x,y) is a solution of
y = 3x + 2.
• (x, f(x)) is a solution of
f(x) = 3x + 2.
• In other words f(x) is the
same thing as y.
Function Notation
•If x = 1 and
f(x) = 3x + 2, then:
•f(1) = 3(1) + 2
•f(1) = 3 + 2
•f(1) = 5
What’s a Function
1
Output
5
Function Notation
•If x = 2 and
f(x) = 3x + 2, then:
•f(2) = 3(2) + 2
•f(2) = 6 + 2
•f(2) = 8
Function Notation
•If x = 5 and
f(x) = 3x + 2, then:
•f(5) = 3(5) + 2
Your Turn
•f(5) = 15 + 2
•f(5) = 17