![Ex 3.4, 2 - Find inverse of [2 1 1 1] - Chapter 3 Matrices - Inverse of matrix using elementary transformation](https://d1avenlh0i1xmr.cloudfront.net/64737029-098f-4111-83d1-82fe46930b41/slide4.jpg)
Ex 3.4, 2
Last updated at Dec. 8, 2016 by Teachoo
Transcript
Ex3.4, 2 Find the inverse of each of the matrices, if it exists.[■8(2&1@1&1)] Let A = [■8(2&1@1&1)] We know that A = IA [■8(2&1@1&1)] = [■8(1&0@0&1)] A R1 →R1 – R2 [■8(𝟐−𝟏&1−1@1&1)] = [■8(1−0&0−1@0&1)] A [■8(𝟏&0@1&1)] = [■8(1&−1@0&1)] A R2 →R2 – R1 [■8(1&0@𝟏−𝟏&1−0)] = [■8(1&−1@0−1&1−(−1))] A [■8(1&0@𝟎&1)] = [■8(1&−1@−1&2)] A I = [■8(1&−1@−1&2)] A This is similar to I = A-1A Thus, A-1 = [■8(1&−1@−1" " &2" " )]
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 7 years. He provides courses for Mathematics and Science from Class 6 to 12. You can learn personally from here https://www.teachoo.com/premium/maths-and-science-classes/.
