Unit 30
Functions
Presentation 1 Functions, Mappings and Domains 1
Presentation 2 Functions, Mapping and Domains 2
Presentation 3 Functions, Mapping and Domains 3
Presentation 4 Composite Functions
Presentation 5 Inverse Functions 1
Presentation 6 Inverse Functions 2
Unit 30
30.1 Functions, Mappings and
Domains 1
Example
If , use the mapping diagram below to show how v
maps to p for . Consider integer values of v.
10
9
8
7
6
5
4
3
2
1
10
9
8
7
6
5
4
3
2
1
Solution
Extension Question
What is the range for p?
Is this 1:1 mapping?
Yes
?
?
v
(domain for p)
p
Unit 30
30.2 Functions, Mapping and
Domains 2
Example
Complete the mapping diagram below for the function
Consider integer values of x.
5
4
3
2
1
0
-1
-2
-3
-4
-5
25
20
15
10
5
0
Solution
Extension Questions
What is the range for y?
Is this 1:1 mapping? No ?
?
Unit 30
30.3 Functions, Mappings and
Domains 3
Example
If f is defined by; for all ,what are the values of:
(a) (b) (c) (d)
Solution
(a)
(b)
(c)
(d)
? ?
?
?
?
?
?
?
?
?
?
?
Extension Question
What is the range of f ?
Sketch the function;
?
x
y
2-2 -1 1
The function f is not
a 1:1 mapping.
Explain why not? all map to 0?
Unit 30
30.4 Composite Functions
The concept of a function of a function is introduced here.
Example
The functions of f and g are defined by
(a)Find and
(b)What are the values of and
Solution
(a) (b) ????
??
?
?
??
????
Unit 30
30.5 Inverse Functions 1
If , we can make C the subject of the equation by
writing
or
We say that F and C are inverse functions.
For inverse functions, f and g, then
Example
Show that if
then
Solution
???
?
?
Note: We write or to mean ,etc.
Unit 30
30.6 Inverse Function 2
For functions that are 1:1 mappings, we can find their inverse
functions.
Example
If , find it’s inverse function.
Solution
?
?
?
?
?
?
?
?
?
?
? ?
i.e.
Let and find x as a function of y.
Check

Math unit30 functions

  • 1.
    Unit 30 Functions Presentation 1Functions, Mappings and Domains 1 Presentation 2 Functions, Mapping and Domains 2 Presentation 3 Functions, Mapping and Domains 3 Presentation 4 Composite Functions Presentation 5 Inverse Functions 1 Presentation 6 Inverse Functions 2
  • 2.
    Unit 30 30.1 Functions,Mappings and Domains 1
  • 3.
    Example If , usethe mapping diagram below to show how v maps to p for . Consider integer values of v. 10 9 8 7 6 5 4 3 2 1 10 9 8 7 6 5 4 3 2 1 Solution Extension Question What is the range for p? Is this 1:1 mapping? Yes ? ? v (domain for p) p
  • 4.
    Unit 30 30.2 Functions,Mapping and Domains 2
  • 5.
    Example Complete the mappingdiagram below for the function Consider integer values of x. 5 4 3 2 1 0 -1 -2 -3 -4 -5 25 20 15 10 5 0 Solution Extension Questions What is the range for y? Is this 1:1 mapping? No ? ?
  • 6.
    Unit 30 30.3 Functions,Mappings and Domains 3
  • 7.
    Example If f isdefined by; for all ,what are the values of: (a) (b) (c) (d) Solution (a) (b) (c) (d) ? ? ? ? ? ? ? ? ? ? ? ? Extension Question What is the range of f ? Sketch the function; ? x y 2-2 -1 1 The function f is not a 1:1 mapping. Explain why not? all map to 0?
  • 8.
  • 9.
    The concept ofa function of a function is introduced here. Example The functions of f and g are defined by (a)Find and (b)What are the values of and Solution (a) (b) ???? ?? ? ? ?? ????
  • 10.
  • 11.
    If , wecan make C the subject of the equation by writing or We say that F and C are inverse functions. For inverse functions, f and g, then Example Show that if then Solution ??? ? ? Note: We write or to mean ,etc.
  • 12.
  • 13.
    For functions thatare 1:1 mappings, we can find their inverse functions. Example If , find it’s inverse function. Solution ? ? ? ? ? ? ? ? ? ? ? ? i.e. Let and find x as a function of y. Check