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 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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FAQs on Linear Transformations - Mathematics Optional Notes for UPSC

1. How do linear transformations work in the context of UPSC exams?
Ans. Linear transformations in the context of UPSC exams refer to the process of transforming one set of coordinates into another set by using a matrix operation. This concept is often tested in the mathematics section of the UPSC exam.
2. Can you provide an example of a linear transformation question that may appear in the UPSC exam?
Ans. An example of a linear transformation question in the UPSC exam could be to find the image of a given vector under a specific transformation matrix, or to determine whether a given matrix represents a valid linear transformation.
3. How important is it to understand linear transformations for UPSC preparation?
Ans. Understanding linear transformations is crucial for UPSC preparation, as it forms the basis of various mathematical concepts that are frequently tested in the exam. It is essential to be familiar with the properties and operations of linear transformations to solve complex problems.
4. What are some tips for mastering linear transformations for the UPSC exam?
Ans. Some tips for mastering linear transformations for the UPSC exam include practicing with a variety of sample questions, understanding the properties of linear transformations thoroughly, and familiarizing yourself with different types of transformation matrices.
5. Are there any specific resources or study materials that can help in improving knowledge of linear transformations for the UPSC exam?
Ans. Yes, there are several resources available online, such as textbooks, video tutorials, and practice questions, that can help improve your understanding of linear transformations for the UPSC exam. It is recommended to utilize these resources to enhance your preparation.
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