![Ex 3.4, 1 - Find inverse of [1 -1 2 3] - Chapter 3 Class 12 - Ex 3.4](https://cdn.teachoo.com/15e434b7-2e7d-47bf-86cf-33008a32cdd9/slide33.jpg)
Question 1 - Inverse of matrix using elementary transformation - Chapter 3 Class 12 Matrices
Last updated at August 2, 2026 by Teachoo
Inverse of matrix using elementary transformation
Elementary operations on a matrix
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Chapter 3 Class 12 Matrices
Concept wise
- Formation and order of matrix
- Types of matrices
- Equal matrices
- Addition/ subtraction of matrices
- Statement questions - Addition/Subtraction of matrices
- Multiplication of matrices
- Statement questions - Multiplication of matrices
- Solving Equation
- Finding unknown - Element
- Finding unknown - Matrice
- Transpose of a matrix
- Symmetric and skew symmetric matrices
- Proof using property of transpose
-
Inverse of matrix using elementary transformation
- Proof using mathematical induction
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Transcript
Ex 3.4, 1 Find the inverse of each of the matrices, if it exists. [■8(1&−1@2&3)] Let A = [■8(1&−1@2&3)] We know that A = IA [■8(1&−1@2&3)] = [■8(1&0@0&1)] A R2 → R2 – 2R1 [■8(1&−1@𝟐−𝟐(𝟏)&3−2(−1))] = [■8(1&0@0−2(1)&1−2(0))] A [■8(1&−1@𝟎&5)] = [■8(1&0@−2&1)] A R2 →1/5 R2 [■8(1&−1@0/5&𝟓/𝟓)] = [■8(1&0@(−2)/5&1/5)] A [■8(1&−1@0&𝟏)] = [■8(1&0@(−2)/5 " " &1/5 " " )] A R1 →R1 + R2 [■8(1+0&−𝟏+𝟏@0&1)] = [■8(1−2/5&0+1/5@(−2)/5 " " &1/5 " " )] A [■8(1&𝟎@0&1)] = [■8(3/5&1/5@(−2)/5 " " &1/5 " " )] A I = [■8(3/5&1/5@(−2)/5 " " &1/5 " " )] A This is similar to I = A-1A Thus, A-1 = [■8(𝟑/𝟓&𝟏/𝟓@(−𝟐)/𝟓 " " &𝟏/𝟓 " " )]
