Page 1
Linear Transformations
Institute of Lifelong Learning pg. 1
Subject: Algebra-I
Lesson: Linear Transformations
Lesson Developer: Chaman Singh
College/Department: Acharya Narendra Dev College (D.U.)
Page 2
Linear Transformations
Institute of Lifelong Learning pg. 1
Subject: Algebra-I
Lesson: Linear Transformations
Lesson Developer: Chaman Singh
College/Department: Acharya Narendra Dev College (D.U.)
Linear Transformations
Institute of Lifelong Learning pg. 2
Table of Contents:
Chapter : Linear Transformations
? 1. Learning Outcomes
? 2. Linear Transformation
? 3. Matrix Transformation
o 3.1. Contraction and Dilation
o 3.2. Shear Transformation
? 4. Matrix of a Linear Transformation
o 4.1. Basis
o 4.2. Steps to find the matrix of the transformation
? Summary
? Exercises
? Glossary
? References/ Bibliography/ Further Reading
1. Learning Outcomes:
After studying the whole contents of this chapter, students will be able to
understand:
? Linear transformation
? Matrix transformation
? Contraction and Dilation
? Shear Transformation
? Matrix of linear transformations
? Basis of linear transformations
? How to find the matrix of a linear transformation
Page 3
Linear Transformations
Institute of Lifelong Learning pg. 1
Subject: Algebra-I
Lesson: Linear Transformations
Lesson Developer: Chaman Singh
College/Department: Acharya Narendra Dev College (D.U.)
Linear Transformations
Institute of Lifelong Learning pg. 2
Table of Contents:
Chapter : Linear Transformations
? 1. Learning Outcomes
? 2. Linear Transformation
? 3. Matrix Transformation
o 3.1. Contraction and Dilation
o 3.2. Shear Transformation
? 4. Matrix of a Linear Transformation
o 4.1. Basis
o 4.2. Steps to find the matrix of the transformation
? Summary
? Exercises
? Glossary
? References/ Bibliography/ Further Reading
1. Learning Outcomes:
After studying the whole contents of this chapter, students will be able to
understand:
? Linear transformation
? Matrix transformation
? Contraction and Dilation
? Shear Transformation
? Matrix of linear transformations
? Basis of linear transformations
? How to find the matrix of a linear transformation
Linear Transformations
Institute of Lifelong Learning pg. 3
2. Linear Transformation:
Consider the Euclidean spaces
nm
R and R . A mapping :
nm
T R R ? is called
the linear mapping or linear transformation if T satisfies the following two
axioms:
( ) ( ) ( ) ( )
( ) ( ) ( )
I T x y T x T y
II T ax aT x
? ? ?
?
Where all ,
n
x y R ? and all aR ? .
Value Addition: Note
The set
n
R is said to be the domain of T, and
m
R co-domain of T.
Value Additions: Do you know?
A mapping or function from X to Y i.e. : f X Y ? is a rule that assigns to
each element x in X a unique element y in Y. The set X is called the
domain of f and the set Y is called the co-domain of f. For , xX ? the
element yY ? , such that f(x) = y, is called the image of x (under the
action of f) and the set of all images yY ? is called the range of f.
Value Addition: Remember
Note: a mapping :
nm
T R R ? is linear if it "preserves" the two basic
operations of a vector space,
(i) vector addition, i.e., ( ) ( ) ( ), , ( ), ( )
nm
T x y T x T y x y R andT x T y R ? ? ? ? ? ? ,
addition of x and y on left is the addition of vectors of
n
R and addition of
T(x) and T(y) on right is addition of vectors of
m
R .
(ii) scalar multiplication, i.e.,
( ) ( ),
n
T ax aT x x R and a R ? ? ? ? ?
Scalar multiplication on left i.e., ax is of vector space
n
R and on right
aT(x) is scalar multiplication of
m
R .
Value Addition: Do you know:
Two axioms in the linear transformations may be written in one condition
only i.e.
Definition: A mapping :
nm
T R R ? is called the linear transformation if it
satisfies the following condition
( ) ( ) ( ), , ,
n
T ax y aT x bT y x y R and a b R ? ? ? ? ? ? ? .
Page 4
Linear Transformations
Institute of Lifelong Learning pg. 1
Subject: Algebra-I
Lesson: Linear Transformations
Lesson Developer: Chaman Singh
College/Department: Acharya Narendra Dev College (D.U.)
Linear Transformations
Institute of Lifelong Learning pg. 2
Table of Contents:
Chapter : Linear Transformations
? 1. Learning Outcomes
? 2. Linear Transformation
? 3. Matrix Transformation
o 3.1. Contraction and Dilation
o 3.2. Shear Transformation
? 4. Matrix of a Linear Transformation
o 4.1. Basis
o 4.2. Steps to find the matrix of the transformation
? Summary
? Exercises
? Glossary
? References/ Bibliography/ Further Reading
1. Learning Outcomes:
After studying the whole contents of this chapter, students will be able to
understand:
? Linear transformation
? Matrix transformation
? Contraction and Dilation
? Shear Transformation
? Matrix of linear transformations
? Basis of linear transformations
? How to find the matrix of a linear transformation
Linear Transformations
Institute of Lifelong Learning pg. 3
2. Linear Transformation:
Consider the Euclidean spaces
nm
R and R . A mapping :
nm
T R R ? is called
the linear mapping or linear transformation if T satisfies the following two
axioms:
( ) ( ) ( ) ( )
( ) ( ) ( )
I T x y T x T y
II T ax aT x
? ? ?
?
Where all ,
n
x y R ? and all aR ? .
Value Addition: Note
The set
n
R is said to be the domain of T, and
m
R co-domain of T.
Value Additions: Do you know?
A mapping or function from X to Y i.e. : f X Y ? is a rule that assigns to
each element x in X a unique element y in Y. The set X is called the
domain of f and the set Y is called the co-domain of f. For , xX ? the
element yY ? , such that f(x) = y, is called the image of x (under the
action of f) and the set of all images yY ? is called the range of f.
Value Addition: Remember
Note: a mapping :
nm
T R R ? is linear if it "preserves" the two basic
operations of a vector space,
(i) vector addition, i.e., ( ) ( ) ( ), , ( ), ( )
nm
T x y T x T y x y R andT x T y R ? ? ? ? ? ? ,
addition of x and y on left is the addition of vectors of
n
R and addition of
T(x) and T(y) on right is addition of vectors of
m
R .
(ii) scalar multiplication, i.e.,
( ) ( ),
n
T ax aT x x R and a R ? ? ? ? ?
Scalar multiplication on left i.e., ax is of vector space
n
R and on right
aT(x) is scalar multiplication of
m
R .
Value Addition: Do you know:
Two axioms in the linear transformations may be written in one condition
only i.e.
Definition: A mapping :
nm
T R R ? is called the linear transformation if it
satisfies the following condition
( ) ( ) ( ), , ,
n
T ax y aT x bT y x y R and a b R ? ? ? ? ? ? ? .
Linear Transformations
Institute of Lifelong Learning pg. 4
Example 1: consider the mapping
32
: T R R ? be defined as
3
1 2 3 1 3 1 2 3
( , , ) ( ,0, ), ( , , ) T x x x x x x x x R ? ? ?
Check whether T is linear or not.
Solution: let
1 2 3 1 2 3
( , , ) ( , , ) X x x x andY y y y ?? be any two vectors of
3
R
(i) vector addition :
1 2 3 1 2 3 1 1 2 2 3 3
( , , ) ( , , ) ( , , ) X Y x x x y y y x y x y x y ? ? ? ? ? ? ?
By definition of T, we have
1 2 3 1 3 1 2 3 1 3
( , , ) ( ,0, ) ( , , ) ( ,0, ) T x x x x x and T y y y y y ??
Now,
1 1 2 2 3 3
1 1 3 3
1 3 1 3
1 2 3 1 2 3
3
( ) ( , , )
( ,0, )
( ,0, ) ( ,0, )
( , , ) ( , , )
( ) ( )
,
T X Y T x y x y x y
x y x y
x x y y
T x x x T y y y
T X T Y
X Y R
? ? ? ? ?
? ? ?
??
??
??
??
(ii) scalar multiplication: For any scalar
3
1 2 3
( , , ) a Randvector X x x x R ? ? ? .
1 2 3 1 2 3
( , , ) ( , , ) aX a x x x ax ax ax ??
Now,
1 2 3
13
13
( ) ( , , )
( ,0, )
( ,0, )
()
T aX T ax ax ax
ax ax
a x x
aT X
?
?
?
?
Thus T satisfies both the axioms therefore T is a linear transformation.
Value Addition: Note
Axiom (i) say that the result T(X + Y) of first adding X and Y in
n
R and
then applying T is same as first applying T to X and Y and then adding
T(X) and T(Y) in
m
R .
Page 5
Linear Transformations
Institute of Lifelong Learning pg. 1
Subject: Algebra-I
Lesson: Linear Transformations
Lesson Developer: Chaman Singh
College/Department: Acharya Narendra Dev College (D.U.)
Linear Transformations
Institute of Lifelong Learning pg. 2
Table of Contents:
Chapter : Linear Transformations
? 1. Learning Outcomes
? 2. Linear Transformation
? 3. Matrix Transformation
o 3.1. Contraction and Dilation
o 3.2. Shear Transformation
? 4. Matrix of a Linear Transformation
o 4.1. Basis
o 4.2. Steps to find the matrix of the transformation
? Summary
? Exercises
? Glossary
? References/ Bibliography/ Further Reading
1. Learning Outcomes:
After studying the whole contents of this chapter, students will be able to
understand:
? Linear transformation
? Matrix transformation
? Contraction and Dilation
? Shear Transformation
? Matrix of linear transformations
? Basis of linear transformations
? How to find the matrix of a linear transformation
Linear Transformations
Institute of Lifelong Learning pg. 3
2. Linear Transformation:
Consider the Euclidean spaces
nm
R and R . A mapping :
nm
T R R ? is called
the linear mapping or linear transformation if T satisfies the following two
axioms:
( ) ( ) ( ) ( )
( ) ( ) ( )
I T x y T x T y
II T ax aT x
? ? ?
?
Where all ,
n
x y R ? and all aR ? .
Value Addition: Note
The set
n
R is said to be the domain of T, and
m
R co-domain of T.
Value Additions: Do you know?
A mapping or function from X to Y i.e. : f X Y ? is a rule that assigns to
each element x in X a unique element y in Y. The set X is called the
domain of f and the set Y is called the co-domain of f. For , xX ? the
element yY ? , such that f(x) = y, is called the image of x (under the
action of f) and the set of all images yY ? is called the range of f.
Value Addition: Remember
Note: a mapping :
nm
T R R ? is linear if it "preserves" the two basic
operations of a vector space,
(i) vector addition, i.e., ( ) ( ) ( ), , ( ), ( )
nm
T x y T x T y x y R andT x T y R ? ? ? ? ? ? ,
addition of x and y on left is the addition of vectors of
n
R and addition of
T(x) and T(y) on right is addition of vectors of
m
R .
(ii) scalar multiplication, i.e.,
( ) ( ),
n
T ax aT x x R and a R ? ? ? ? ?
Scalar multiplication on left i.e., ax is of vector space
n
R and on right
aT(x) is scalar multiplication of
m
R .
Value Addition: Do you know:
Two axioms in the linear transformations may be written in one condition
only i.e.
Definition: A mapping :
nm
T R R ? is called the linear transformation if it
satisfies the following condition
( ) ( ) ( ), , ,
n
T ax y aT x bT y x y R and a b R ? ? ? ? ? ? ? .
Linear Transformations
Institute of Lifelong Learning pg. 4
Example 1: consider the mapping
32
: T R R ? be defined as
3
1 2 3 1 3 1 2 3
( , , ) ( ,0, ), ( , , ) T x x x x x x x x R ? ? ?
Check whether T is linear or not.
Solution: let
1 2 3 1 2 3
( , , ) ( , , ) X x x x andY y y y ?? be any two vectors of
3
R
(i) vector addition :
1 2 3 1 2 3 1 1 2 2 3 3
( , , ) ( , , ) ( , , ) X Y x x x y y y x y x y x y ? ? ? ? ? ? ?
By definition of T, we have
1 2 3 1 3 1 2 3 1 3
( , , ) ( ,0, ) ( , , ) ( ,0, ) T x x x x x and T y y y y y ??
Now,
1 1 2 2 3 3
1 1 3 3
1 3 1 3
1 2 3 1 2 3
3
( ) ( , , )
( ,0, )
( ,0, ) ( ,0, )
( , , ) ( , , )
( ) ( )
,
T X Y T x y x y x y
x y x y
x x y y
T x x x T y y y
T X T Y
X Y R
? ? ? ? ?
? ? ?
??
??
??
??
(ii) scalar multiplication: For any scalar
3
1 2 3
( , , ) a Randvector X x x x R ? ? ? .
1 2 3 1 2 3
( , , ) ( , , ) aX a x x x ax ax ax ??
Now,
1 2 3
13
13
( ) ( , , )
( ,0, )
( ,0, )
()
T aX T ax ax ax
ax ax
a x x
aT X
?
?
?
?
Thus T satisfies both the axioms therefore T is a linear transformation.
Value Addition: Note
Axiom (i) say that the result T(X + Y) of first adding X and Y in
n
R and
then applying T is same as first applying T to X and Y and then adding
T(X) and T(Y) in
m
R .
Linear Transformations
Institute of Lifelong Learning pg. 5
Alternative method: instead of satisfying the two axioms, we will satisfy
the single axiom, i.e., for all ,, a b R ? we have
1 2 3 1 2 3
1 2 3 1 2 3
1 1 2 2 3 3
( , , ) ( , , )
( , , ) ( , , )
( , , )
aX bY a x x x b y y y
ax ax ax by by by
aX bY ax by ax by ax by
? ? ?
??
? ? ? ? ?
Thus,
1 1 2 2 3 3
1 1 3 3
1 3 1 3
1 3 1 3
( ) ( , , )
( ,0, )
( ,0, ) ( ,0, )
( ,0, ) ( ,0, )
( ) ( )
T aX bY T ax by ax by ax by
ax by ax by
ax ax by by
a x x b y y
aT X bT Y
? ? ? ? ?
? ? ?
??
??
??
Thus, we have ( ) ( ) ( ) T aX bY aT X bT Y ? ? ?
Hence, T is a linear transformation.
Value Addition: Do you know?
Every linear transformation maps the zero vector of
n
R onto the zero
vector of
m
R . I.e., (0) 0 T ? .
Example 2: consider the mapping
23
: T R R ? defined by
1 2 1 2 1 2 1 2
( , ) ( 1,2 , 3 ) T x x x x x x x x ? ? ? ? ?
Check whether T is linear or not.
Solution: Let
1 2 1 2
( , ) ( , ) X x x and Y y y ?? be any two vectors of
2
R . By the
definition of the mapping, we have
12
1 2 1 2 1 2
( ) ( , )
( 1,2 , 3 )
T X T x x
x x x x x x
?
? ? ? ? ?
(1)
And
1 2 1 3
1 2 1 2 1 2
( ) ( , ) ( ,0, )
( 1,2 , 3 )
T Y T y y y y
y y y y y y
??
? ? ? ? ?
(2)
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