cbse class ncert solution chapter - 3 matrices - exercise
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CBSE Class–12 Mathematics
NCERT solution Chapter - 3
Matrices - Exercise 3.4
Using elementary transformation, find the inverse of each of the matrices, if it exists in
Exercises 1 to 6.
1.
Ans. Let A =
Since A = IA
=
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2.
Ans. Let A =
3.
Ans. Let A =
Since A = IA
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=
4.
Ans. Let A =
Since A = IA
=
5.
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Ans. Let A =
Since A = IA
=
6.
Ans. Let A =
Since A = IA
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=
Using elementary transformation, find the inverse of each of the matrices, if it exists in
Exercises 7 to 14.
7.
Ans. Let A =
Since A = IA
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=
8.
Ans. Let A =
Since A = IA
=
9.
Ans. Let A =
Since A = IA
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=
10.
Ans. Let A =
Since A = IA
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=
11.
Ans. Let A =
Since A = IA
=
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12.
Ans. Let A =
Since A = IA
Here, all entries in second row of left side are zero.
does not exist.
13.
Ans. Let A =
Since A = IA
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=
14.
Ans. Let A =
Since A = IA
Here, all entries in second row of left side are zero.
does not exist.
15.
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Ans. Let A = ,
We know that A = IA,
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16.
Ans. Let A = ,
Since, A = IA
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=
17.
Ans. Let A = ,
Since, A = IA
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=
18. Matrices A and B will be inverse of each other only if:
(A) AB = BA
(B) AB = BA = 0
(C) AB = 0, BA = I
(D) AB = BA = I
Ans. By definition of inverse of square matrix,
Option (D) is correct. www.scho
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