Page 1
Edurev123
2. Linear Transformations
Q 2.1 Let ?? ={(?? ,?? ,?? ),(?? ,?? ,?? ),(?? ,?? ,?? )} and ?? '
={(?? ,?? ,?? ),(?? ,?? ,?? ),(-?? ,?? ,?? )} be the
two order bases of ?? ?? . Then find the matrix representing the linear transformation
?? :?? ?? ??? ?? which transforms ?? into ?? '
. Use this matrix transformation to find ?? (???)
where ??? =(?? ,?? ,?? ) .
Solution:
Insight: A change of basis matrix from ?? to ?? '
expresses the coordinates with respect to
basis ?? '
in terms of coordinates w.r.t. to ?? .
First we express elements of ?? '
in terms of ?? .
Let (?? ,?? ,?? ) any general vector be expressed as linear combination of elements of ?? .
(?? ,?? ,?? )=(1,1,0)?? +(1,0,1)?? +(0,1,1)??
? [
1 1 0
1 0 1
0 1 1
][
?? ?? ?? ]=[
?? ?? ?? ]
Using the augmented matrix to solve the linear system of equations
[
1 1 0 ? ?? 1 0 1 ? ?? 0 1 1 ? ?? ]?? 2
??? 2
-?? 1
[
1 1 0 ? ?? 0 -1 1 ? ?? -?? 0 1 1 ? ?? ]
?? 2
?-1?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 1 1 ? ?? ]?? 3
??? 3
-?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 0 2 ? ?? +?? -?? ]
?? =
?? +?? -?? 2
;?? =
?? -?? +?? 2
;?? =
?? +?? -?? 2
We use this to express elements of ?? '
as coordinates of ?? .
(2,1,1) =1?? 1
+1?? 2
+0?? 3
(1,2,1) =1?? 1
+0?? 2
+1?? 3
(-1,1,1) =
-1
2
?? 1
+
-1
2
?? 2
+
3
2
?? 3
So change of basis matrix is
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
(2,1,1)=(1,1,0)(
2+1-1
2
)+(1,0,1)(
2-1+1
2
)
Page 2
Edurev123
2. Linear Transformations
Q 2.1 Let ?? ={(?? ,?? ,?? ),(?? ,?? ,?? ),(?? ,?? ,?? )} and ?? '
={(?? ,?? ,?? ),(?? ,?? ,?? ),(-?? ,?? ,?? )} be the
two order bases of ?? ?? . Then find the matrix representing the linear transformation
?? :?? ?? ??? ?? which transforms ?? into ?? '
. Use this matrix transformation to find ?? (???)
where ??? =(?? ,?? ,?? ) .
Solution:
Insight: A change of basis matrix from ?? to ?? '
expresses the coordinates with respect to
basis ?? '
in terms of coordinates w.r.t. to ?? .
First we express elements of ?? '
in terms of ?? .
Let (?? ,?? ,?? ) any general vector be expressed as linear combination of elements of ?? .
(?? ,?? ,?? )=(1,1,0)?? +(1,0,1)?? +(0,1,1)??
? [
1 1 0
1 0 1
0 1 1
][
?? ?? ?? ]=[
?? ?? ?? ]
Using the augmented matrix to solve the linear system of equations
[
1 1 0 ? ?? 1 0 1 ? ?? 0 1 1 ? ?? ]?? 2
??? 2
-?? 1
[
1 1 0 ? ?? 0 -1 1 ? ?? -?? 0 1 1 ? ?? ]
?? 2
?-1?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 1 1 ? ?? ]?? 3
??? 3
-?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 0 2 ? ?? +?? -?? ]
?? =
?? +?? -?? 2
;?? =
?? -?? +?? 2
;?? =
?? +?? -?? 2
We use this to express elements of ?? '
as coordinates of ?? .
(2,1,1) =1?? 1
+1?? 2
+0?? 3
(1,2,1) =1?? 1
+0?? 2
+1?? 3
(-1,1,1) =
-1
2
?? 1
+
-1
2
?? 2
+
3
2
?? 3
So change of basis matrix is
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
(2,1,1)=(1,1,0)(
2+1-1
2
)+(1,0,1)(
2-1+1
2
)
?? ,?? ,?? =1,1,0
Similarly, (?? 2
,?? 2
,?? 2
) and (?? 3
,?? 3
,?? 3
) matrix is
=[
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
]
?? (???) =?? ·??˜
'
=
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
[
2
3
1
]=[
9/2
3/2
9/2
]
Q 2.2 Let ?? :?? ?? ??? ?? be a linear transformation defined by
?? ((?? ?? ,?? ?? ,?? ?? ,?? ?? ))=(?? ?? +?? ?? -?? ?? -?? ?? ,?? ?? -?? ?? ,?? ?? -?? ?? )
Then find the rank and nullify of ?? . Also determine null space and range space of
?? .
(2009 : 20 Marks)
Solution:
Approach: We could use the standard basis vectors of ?? 4
or use the matrix form of the
linear transformation. Let (?? 1
,?? 2
,?? 3
,?? 4
)=?? be the standard basis of ?? 4
where ?? 1
=
(1,0,0,0) and similar to others.
?? =(?? 1
,?? 2
,?? 3
,?? 4
) spans ?? 4
so {?? (?? 1
),?? (?? 2
),?? (?? 3
),?? (?? 4
)} will span ???? (?? ) , i.e., image
space of ?? . So a linear independent subspace will be basis of range space and its
dimension rank.
?? (?? 1
)=(-1,0,-1)
?? (?? 2
)=(-1,-1,0)
?? ?? 3
)=(1,1,0)
?? ?? 4
)=(1,0,1)
To reduce it to a linearly independent subset we reduce the matrix with the vectors as
row to row reduced echelon form
[
-1 0 -1
-1 -1 0
1 1 0
1 0 1
] ?
?? 1
??? 3
?? 2
??? 4
[
1 1 0
1 0 1
-1 0 -1
-1 -1 0
]
=
?? 1
?? 2
??? 2
-?? 4
?? 4
??? 4
+?? 1
[
1 1 0
0 -1 1
0 1 -1
0 0 0
] ?
?? 2
?-1?? 2
?? 3
??? 3
-?? 2
[
1 1 0
0 1 -1
0 0 0
0 0 0
]
Page 3
Edurev123
2. Linear Transformations
Q 2.1 Let ?? ={(?? ,?? ,?? ),(?? ,?? ,?? ),(?? ,?? ,?? )} and ?? '
={(?? ,?? ,?? ),(?? ,?? ,?? ),(-?? ,?? ,?? )} be the
two order bases of ?? ?? . Then find the matrix representing the linear transformation
?? :?? ?? ??? ?? which transforms ?? into ?? '
. Use this matrix transformation to find ?? (???)
where ??? =(?? ,?? ,?? ) .
Solution:
Insight: A change of basis matrix from ?? to ?? '
expresses the coordinates with respect to
basis ?? '
in terms of coordinates w.r.t. to ?? .
First we express elements of ?? '
in terms of ?? .
Let (?? ,?? ,?? ) any general vector be expressed as linear combination of elements of ?? .
(?? ,?? ,?? )=(1,1,0)?? +(1,0,1)?? +(0,1,1)??
? [
1 1 0
1 0 1
0 1 1
][
?? ?? ?? ]=[
?? ?? ?? ]
Using the augmented matrix to solve the linear system of equations
[
1 1 0 ? ?? 1 0 1 ? ?? 0 1 1 ? ?? ]?? 2
??? 2
-?? 1
[
1 1 0 ? ?? 0 -1 1 ? ?? -?? 0 1 1 ? ?? ]
?? 2
?-1?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 1 1 ? ?? ]?? 3
??? 3
-?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 0 2 ? ?? +?? -?? ]
?? =
?? +?? -?? 2
;?? =
?? -?? +?? 2
;?? =
?? +?? -?? 2
We use this to express elements of ?? '
as coordinates of ?? .
(2,1,1) =1?? 1
+1?? 2
+0?? 3
(1,2,1) =1?? 1
+0?? 2
+1?? 3
(-1,1,1) =
-1
2
?? 1
+
-1
2
?? 2
+
3
2
?? 3
So change of basis matrix is
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
(2,1,1)=(1,1,0)(
2+1-1
2
)+(1,0,1)(
2-1+1
2
)
?? ,?? ,?? =1,1,0
Similarly, (?? 2
,?? 2
,?? 2
) and (?? 3
,?? 3
,?? 3
) matrix is
=[
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
]
?? (???) =?? ·??˜
'
=
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
[
2
3
1
]=[
9/2
3/2
9/2
]
Q 2.2 Let ?? :?? ?? ??? ?? be a linear transformation defined by
?? ((?? ?? ,?? ?? ,?? ?? ,?? ?? ))=(?? ?? +?? ?? -?? ?? -?? ?? ,?? ?? -?? ?? ,?? ?? -?? ?? )
Then find the rank and nullify of ?? . Also determine null space and range space of
?? .
(2009 : 20 Marks)
Solution:
Approach: We could use the standard basis vectors of ?? 4
or use the matrix form of the
linear transformation. Let (?? 1
,?? 2
,?? 3
,?? 4
)=?? be the standard basis of ?? 4
where ?? 1
=
(1,0,0,0) and similar to others.
?? =(?? 1
,?? 2
,?? 3
,?? 4
) spans ?? 4
so {?? (?? 1
),?? (?? 2
),?? (?? 3
),?? (?? 4
)} will span ???? (?? ) , i.e., image
space of ?? . So a linear independent subspace will be basis of range space and its
dimension rank.
?? (?? 1
)=(-1,0,-1)
?? (?? 2
)=(-1,-1,0)
?? ?? 3
)=(1,1,0)
?? ?? 4
)=(1,0,1)
To reduce it to a linearly independent subset we reduce the matrix with the vectors as
row to row reduced echelon form
[
-1 0 -1
-1 -1 0
1 1 0
1 0 1
] ?
?? 1
??? 3
?? 2
??? 4
[
1 1 0
1 0 1
-1 0 -1
-1 -1 0
]
=
?? 1
?? 2
??? 2
-?? 4
?? 4
??? 4
+?? 1
[
1 1 0
0 -1 1
0 1 -1
0 0 0
] ?
?? 2
?-1?? 2
?? 3
??? 3
-?? 2
[
1 1 0
0 1 -1
0 0 0
0 0 0
]
??? '
={(1,1,0),(0,1,-1)} is a linearly independent subset which spans Im (?? ) .
? Rank (?? ) =2
and Range Space = Linear Span {(1,1,0),(0,1,-1)}
Nullify and Null Space ?? ??? 4
is in null space if ?? (?? )=0
? [
?? 3
+?? 4
-?? 1
-?? 2
?? 3
-?? 2
?? 4
-?? 1
]=[
0
0
0
]
Thus, there are two free variables ?? 1
and ?? 2
and so nullify = dim (null space) =2.
Giving arbitrary value to free variables
?? 1
=1,?? 2
=0 (?? 1
,?? 2
,?? 3
,?? 4
)
=(1,0,0,1)
?? 2
=0,?? 2
=1 (?? 1
,?? 2
,?? 3
,?? 4
)
=(0,1,1,0)
?{(1,0,0,1),(0,1,1,0} is a basis for null space of ?? .
Q 2.3. What is the null space of the differential transformation
?? ????
:?? ?? ??? ?? where
?? ?? is the space of all polynomials of degree =?? are the real numbers? What is the
null space of second derivative as a transformation of ?? ?? ? What is the null space
of ?? th derivative?
(2010 : 12 Marks)
Solution:
Let the polynomial
?????? , ?? ?? (?? )=?? 0
+?? 1
?? +?? 2
?? 2
+?..+?? ?? ?? ?? ????
?? ????
?? ?? (?? )=?? 1
+2?? 2
?? +3?? 3
?? 2
+?..+?? ?? ?? ?? ?? -1
???? ?? ?? (?? )=0??? 1
+2?? 2
?? +?…+?? ?? ?? ?? ?? -1
=0
?? h???? ?? 1
=?? 2
=?…=?? ?? =0
? Null space of the transformation
?? ????
?? ?? (?? )??? ?? (?? ) is
i.e.,
Page 4
Edurev123
2. Linear Transformations
Q 2.1 Let ?? ={(?? ,?? ,?? ),(?? ,?? ,?? ),(?? ,?? ,?? )} and ?? '
={(?? ,?? ,?? ),(?? ,?? ,?? ),(-?? ,?? ,?? )} be the
two order bases of ?? ?? . Then find the matrix representing the linear transformation
?? :?? ?? ??? ?? which transforms ?? into ?? '
. Use this matrix transformation to find ?? (???)
where ??? =(?? ,?? ,?? ) .
Solution:
Insight: A change of basis matrix from ?? to ?? '
expresses the coordinates with respect to
basis ?? '
in terms of coordinates w.r.t. to ?? .
First we express elements of ?? '
in terms of ?? .
Let (?? ,?? ,?? ) any general vector be expressed as linear combination of elements of ?? .
(?? ,?? ,?? )=(1,1,0)?? +(1,0,1)?? +(0,1,1)??
? [
1 1 0
1 0 1
0 1 1
][
?? ?? ?? ]=[
?? ?? ?? ]
Using the augmented matrix to solve the linear system of equations
[
1 1 0 ? ?? 1 0 1 ? ?? 0 1 1 ? ?? ]?? 2
??? 2
-?? 1
[
1 1 0 ? ?? 0 -1 1 ? ?? -?? 0 1 1 ? ?? ]
?? 2
?-1?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 1 1 ? ?? ]?? 3
??? 3
-?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 0 2 ? ?? +?? -?? ]
?? =
?? +?? -?? 2
;?? =
?? -?? +?? 2
;?? =
?? +?? -?? 2
We use this to express elements of ?? '
as coordinates of ?? .
(2,1,1) =1?? 1
+1?? 2
+0?? 3
(1,2,1) =1?? 1
+0?? 2
+1?? 3
(-1,1,1) =
-1
2
?? 1
+
-1
2
?? 2
+
3
2
?? 3
So change of basis matrix is
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
(2,1,1)=(1,1,0)(
2+1-1
2
)+(1,0,1)(
2-1+1
2
)
?? ,?? ,?? =1,1,0
Similarly, (?? 2
,?? 2
,?? 2
) and (?? 3
,?? 3
,?? 3
) matrix is
=[
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
]
?? (???) =?? ·??˜
'
=
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
[
2
3
1
]=[
9/2
3/2
9/2
]
Q 2.2 Let ?? :?? ?? ??? ?? be a linear transformation defined by
?? ((?? ?? ,?? ?? ,?? ?? ,?? ?? ))=(?? ?? +?? ?? -?? ?? -?? ?? ,?? ?? -?? ?? ,?? ?? -?? ?? )
Then find the rank and nullify of ?? . Also determine null space and range space of
?? .
(2009 : 20 Marks)
Solution:
Approach: We could use the standard basis vectors of ?? 4
or use the matrix form of the
linear transformation. Let (?? 1
,?? 2
,?? 3
,?? 4
)=?? be the standard basis of ?? 4
where ?? 1
=
(1,0,0,0) and similar to others.
?? =(?? 1
,?? 2
,?? 3
,?? 4
) spans ?? 4
so {?? (?? 1
),?? (?? 2
),?? (?? 3
),?? (?? 4
)} will span ???? (?? ) , i.e., image
space of ?? . So a linear independent subspace will be basis of range space and its
dimension rank.
?? (?? 1
)=(-1,0,-1)
?? (?? 2
)=(-1,-1,0)
?? ?? 3
)=(1,1,0)
?? ?? 4
)=(1,0,1)
To reduce it to a linearly independent subset we reduce the matrix with the vectors as
row to row reduced echelon form
[
-1 0 -1
-1 -1 0
1 1 0
1 0 1
] ?
?? 1
??? 3
?? 2
??? 4
[
1 1 0
1 0 1
-1 0 -1
-1 -1 0
]
=
?? 1
?? 2
??? 2
-?? 4
?? 4
??? 4
+?? 1
[
1 1 0
0 -1 1
0 1 -1
0 0 0
] ?
?? 2
?-1?? 2
?? 3
??? 3
-?? 2
[
1 1 0
0 1 -1
0 0 0
0 0 0
]
??? '
={(1,1,0),(0,1,-1)} is a linearly independent subset which spans Im (?? ) .
? Rank (?? ) =2
and Range Space = Linear Span {(1,1,0),(0,1,-1)}
Nullify and Null Space ?? ??? 4
is in null space if ?? (?? )=0
? [
?? 3
+?? 4
-?? 1
-?? 2
?? 3
-?? 2
?? 4
-?? 1
]=[
0
0
0
]
Thus, there are two free variables ?? 1
and ?? 2
and so nullify = dim (null space) =2.
Giving arbitrary value to free variables
?? 1
=1,?? 2
=0 (?? 1
,?? 2
,?? 3
,?? 4
)
=(1,0,0,1)
?? 2
=0,?? 2
=1 (?? 1
,?? 2
,?? 3
,?? 4
)
=(0,1,1,0)
?{(1,0,0,1),(0,1,1,0} is a basis for null space of ?? .
Q 2.3. What is the null space of the differential transformation
?? ????
:?? ?? ??? ?? where
?? ?? is the space of all polynomials of degree =?? are the real numbers? What is the
null space of second derivative as a transformation of ?? ?? ? What is the null space
of ?? th derivative?
(2010 : 12 Marks)
Solution:
Let the polynomial
?????? , ?? ?? (?? )=?? 0
+?? 1
?? +?? 2
?? 2
+?..+?? ?? ?? ?? ????
?? ????
?? ?? (?? )=?? 1
+2?? 2
?? +3?? 3
?? 2
+?..+?? ?? ?? ?? ?? -1
???? ?? ?? (?? )=0??? 1
+2?? 2
?? +?…+?? ?? ?? ?? ?? -1
=0
?? h???? ?? 1
=?? 2
=?…=?? ?? =0
? Null space of the transformation
?? ????
?? ?? (?? )??? ?? (?? ) is
i.e.,
?? 1
=?? 2
=?..=?? ?? =0 and ?? 0
??? ??.?? .(?? 0
,?? 1
,?? 2
,…,?? ?? ) =?? 0
(1,0,0,……,0)
?????? ,
?? 2
?? ?? ?? ?? (?? ) =2?? 2
+6?? 3
+?..+?? (?? -1)?? ????
?? ?? -2
=0
?? h???? ,?? 2
=?? 3
=?..=?? ?? =0
? Null space of
?? 2
????
?? ?? (?? ) is when ?? 0
,?? 1
??? and ?? 2
=?? 3
=?.?? ?? =0
So, dimension of nuil space of ?? th
derivative is ?? .
So,
Null space =?? 0
(1,0,0,……,0)+?? 1
(0,1,0,….,0)
?? ?? ????
?? ?? =?? !?? ?? +(?? +1)!?? ?? +1
+?..+?? (?? -1)(?? -2)….(?? -?? +1)?? ?? ?? ?? -?? =0
when
?? ?? =???? +1=?=???? -1=???? =0
and ?? 0
??? ,?? 1
??? 1
…..?? ?? -?? ???
So, null space of ?? th
derivative is ?? 0
(1,0,….,0)+?? 1
(0,1,….,0)+?..+?? ?? (0,0,…..1,0,0,0)
2.4 Let ?? =(
?? ?? ?? ?? ?? ?? ) . Find the unique linear transformation ?? :?? ?? ??? ?? so that ??
is the matrix of ?? with respect to the basis.
?? ={?? ?? =(?? ,?? ,?? ),?? ?? =(?? ,?? ,?? ),?? ?? =(?? ,?? ,?? )}
of ?? ?? and ?? '
=[?? ?? =(?? ,?? ),?? ?? =(?? ,?? )} of ?? ?? . Also find ?? (?? ,?? ,?? ) .
(2010: 20 Marks)
Solution:
Given ?? is the basis of ?? 3
and ?? '
be basis of ?? ?? for transformation ?? .
Now,
?? (?? 1
) =?? (1,0,0)=4?? 1
+0?? 2
=4(1,0)+0.(1,1)=(4,0)
?? (?? 2
) =?? (1,1,0)=2w1+1?? 2
=2(1,0)+1(1,1)=(3,1)
?? (?? 3
) =?? (1,1,1)=1.?? 1
+3.?? 2
=1.(1,0)+3(1,1)=(4,3)
Page 5
Edurev123
2. Linear Transformations
Q 2.1 Let ?? ={(?? ,?? ,?? ),(?? ,?? ,?? ),(?? ,?? ,?? )} and ?? '
={(?? ,?? ,?? ),(?? ,?? ,?? ),(-?? ,?? ,?? )} be the
two order bases of ?? ?? . Then find the matrix representing the linear transformation
?? :?? ?? ??? ?? which transforms ?? into ?? '
. Use this matrix transformation to find ?? (???)
where ??? =(?? ,?? ,?? ) .
Solution:
Insight: A change of basis matrix from ?? to ?? '
expresses the coordinates with respect to
basis ?? '
in terms of coordinates w.r.t. to ?? .
First we express elements of ?? '
in terms of ?? .
Let (?? ,?? ,?? ) any general vector be expressed as linear combination of elements of ?? .
(?? ,?? ,?? )=(1,1,0)?? +(1,0,1)?? +(0,1,1)??
? [
1 1 0
1 0 1
0 1 1
][
?? ?? ?? ]=[
?? ?? ?? ]
Using the augmented matrix to solve the linear system of equations
[
1 1 0 ? ?? 1 0 1 ? ?? 0 1 1 ? ?? ]?? 2
??? 2
-?? 1
[
1 1 0 ? ?? 0 -1 1 ? ?? -?? 0 1 1 ? ?? ]
?? 2
?-1?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 1 1 ? ?? ]?? 3
??? 3
-?? 2
[
1 1 0 ? ?? 0 1 -1 ? ?? -?? 0 0 2 ? ?? +?? -?? ]
?? =
?? +?? -?? 2
;?? =
?? -?? +?? 2
;?? =
?? +?? -?? 2
We use this to express elements of ?? '
as coordinates of ?? .
(2,1,1) =1?? 1
+1?? 2
+0?? 3
(1,2,1) =1?? 1
+0?? 2
+1?? 3
(-1,1,1) =
-1
2
?? 1
+
-1
2
?? 2
+
3
2
?? 3
So change of basis matrix is
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
(2,1,1)=(1,1,0)(
2+1-1
2
)+(1,0,1)(
2-1+1
2
)
?? ,?? ,?? =1,1,0
Similarly, (?? 2
,?? 2
,?? 2
) and (?? 3
,?? 3
,?? 3
) matrix is
=[
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
?? 1
?? 2
?? 3
]
?? (???) =?? ·??˜
'
=
[
1 1 -
1
2
1 0 -
1
2
0 1
3
2
]
[
2
3
1
]=[
9/2
3/2
9/2
]
Q 2.2 Let ?? :?? ?? ??? ?? be a linear transformation defined by
?? ((?? ?? ,?? ?? ,?? ?? ,?? ?? ))=(?? ?? +?? ?? -?? ?? -?? ?? ,?? ?? -?? ?? ,?? ?? -?? ?? )
Then find the rank and nullify of ?? . Also determine null space and range space of
?? .
(2009 : 20 Marks)
Solution:
Approach: We could use the standard basis vectors of ?? 4
or use the matrix form of the
linear transformation. Let (?? 1
,?? 2
,?? 3
,?? 4
)=?? be the standard basis of ?? 4
where ?? 1
=
(1,0,0,0) and similar to others.
?? =(?? 1
,?? 2
,?? 3
,?? 4
) spans ?? 4
so {?? (?? 1
),?? (?? 2
),?? (?? 3
),?? (?? 4
)} will span ???? (?? ) , i.e., image
space of ?? . So a linear independent subspace will be basis of range space and its
dimension rank.
?? (?? 1
)=(-1,0,-1)
?? (?? 2
)=(-1,-1,0)
?? ?? 3
)=(1,1,0)
?? ?? 4
)=(1,0,1)
To reduce it to a linearly independent subset we reduce the matrix with the vectors as
row to row reduced echelon form
[
-1 0 -1
-1 -1 0
1 1 0
1 0 1
] ?
?? 1
??? 3
?? 2
??? 4
[
1 1 0
1 0 1
-1 0 -1
-1 -1 0
]
=
?? 1
?? 2
??? 2
-?? 4
?? 4
??? 4
+?? 1
[
1 1 0
0 -1 1
0 1 -1
0 0 0
] ?
?? 2
?-1?? 2
?? 3
??? 3
-?? 2
[
1 1 0
0 1 -1
0 0 0
0 0 0
]
??? '
={(1,1,0),(0,1,-1)} is a linearly independent subset which spans Im (?? ) .
? Rank (?? ) =2
and Range Space = Linear Span {(1,1,0),(0,1,-1)}
Nullify and Null Space ?? ??? 4
is in null space if ?? (?? )=0
? [
?? 3
+?? 4
-?? 1
-?? 2
?? 3
-?? 2
?? 4
-?? 1
]=[
0
0
0
]
Thus, there are two free variables ?? 1
and ?? 2
and so nullify = dim (null space) =2.
Giving arbitrary value to free variables
?? 1
=1,?? 2
=0 (?? 1
,?? 2
,?? 3
,?? 4
)
=(1,0,0,1)
?? 2
=0,?? 2
=1 (?? 1
,?? 2
,?? 3
,?? 4
)
=(0,1,1,0)
?{(1,0,0,1),(0,1,1,0} is a basis for null space of ?? .
Q 2.3. What is the null space of the differential transformation
?? ????
:?? ?? ??? ?? where
?? ?? is the space of all polynomials of degree =?? are the real numbers? What is the
null space of second derivative as a transformation of ?? ?? ? What is the null space
of ?? th derivative?
(2010 : 12 Marks)
Solution:
Let the polynomial
?????? , ?? ?? (?? )=?? 0
+?? 1
?? +?? 2
?? 2
+?..+?? ?? ?? ?? ????
?? ????
?? ?? (?? )=?? 1
+2?? 2
?? +3?? 3
?? 2
+?..+?? ?? ?? ?? ?? -1
???? ?? ?? (?? )=0??? 1
+2?? 2
?? +?…+?? ?? ?? ?? ?? -1
=0
?? h???? ?? 1
=?? 2
=?…=?? ?? =0
? Null space of the transformation
?? ????
?? ?? (?? )??? ?? (?? ) is
i.e.,
?? 1
=?? 2
=?..=?? ?? =0 and ?? 0
??? ??.?? .(?? 0
,?? 1
,?? 2
,…,?? ?? ) =?? 0
(1,0,0,……,0)
?????? ,
?? 2
?? ?? ?? ?? (?? ) =2?? 2
+6?? 3
+?..+?? (?? -1)?? ????
?? ?? -2
=0
?? h???? ,?? 2
=?? 3
=?..=?? ?? =0
? Null space of
?? 2
????
?? ?? (?? ) is when ?? 0
,?? 1
??? and ?? 2
=?? 3
=?.?? ?? =0
So, dimension of nuil space of ?? th
derivative is ?? .
So,
Null space =?? 0
(1,0,0,……,0)+?? 1
(0,1,0,….,0)
?? ?? ????
?? ?? =?? !?? ?? +(?? +1)!?? ?? +1
+?..+?? (?? -1)(?? -2)….(?? -?? +1)?? ?? ?? ?? -?? =0
when
?? ?? =???? +1=?=???? -1=???? =0
and ?? 0
??? ,?? 1
??? 1
…..?? ?? -?? ???
So, null space of ?? th
derivative is ?? 0
(1,0,….,0)+?? 1
(0,1,….,0)+?..+?? ?? (0,0,…..1,0,0,0)
2.4 Let ?? =(
?? ?? ?? ?? ?? ?? ) . Find the unique linear transformation ?? :?? ?? ??? ?? so that ??
is the matrix of ?? with respect to the basis.
?? ={?? ?? =(?? ,?? ,?? ),?? ?? =(?? ,?? ,?? ),?? ?? =(?? ,?? ,?? )}
of ?? ?? and ?? '
=[?? ?? =(?? ,?? ),?? ?? =(?? ,?? )} of ?? ?? . Also find ?? (?? ,?? ,?? ) .
(2010: 20 Marks)
Solution:
Given ?? is the basis of ?? 3
and ?? '
be basis of ?? ?? for transformation ?? .
Now,
?? (?? 1
) =?? (1,0,0)=4?? 1
+0?? 2
=4(1,0)+0.(1,1)=(4,0)
?? (?? 2
) =?? (1,1,0)=2w1+1?? 2
=2(1,0)+1(1,1)=(3,1)
?? (?? 3
) =?? (1,1,1)=1.?? 1
+3.?? 2
=1.(1,0)+3(1,1)=(4,3)
Now, let
(?? ,?? ,?? )=?? (1,0,0)+?? (1,1,0)+?? (1,1,1)=?? ?? 1
+?? ?? 2
+?? ?? 3
(?? ,?? ,?? )=(?? +?? +?? ,?? +?? ,?? )
Comparing LHS & RHS, we get
?? =?? (?? ,?? ,?? ) =(?? -?? )·?? 1
+(?? -?? )·?? 2
+?? ·?? 3
? ?? (?? ,?? ,?? ) =?? ((?? -?? )·?? 1
+(?? -?? )·?? 2
+?? ·?? 3
)
=(?? -?? )?? (?? 1
)+(?? -?? )?? (?? 2
)+?? ·?? (?? 3
)
=(?? -?? )(4,0)+(?? -?? )(3,1)+?? (4,3)
=(4(?? -?? ),0)+(3(?? -?? ),(?? -?? )+(4?? ,3?? )
=(4?? -4?? +3?? -3?? +4?? ,0+?? -?? +3?? )
=(4?? -?? +?? ,?? +2?? )
? The transformation ?? is ?? (?? ,?? ,?? )=(4?? -?? +?? ,?? +2?? )
2.5 Let ?? be a linear transformation from a vector space V over reals into ?? such
that ?? -?? ?? =?? . Show that ?? is invertible.
(2010 : 10 Marks)
Solution:
Given, ?? be the linear transformation, such that
?? -?? 2
=?? ? ?? (?? -?? ) =?? ? ?? (?? -?? ) =?? ? |?? ||(?? -?? )| =|?? |, i.e., |?? |×|?? -?? |=1
|?? | ?0
??? is invertible.
Q 2.6 Find the nullity and a basis of the null space of the linear transformation
?? :?? (?? )??? (?? ) given by the matrix
?? =[
?? ?? -?? -?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? -?? ?? ]
(2011 : 10 Marks)
Solution :
Let ?? ={?? 1
,?? 2
,?? 3
,?? 4
} be the usual basis of ?? 4
.
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