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Ex 3.4, 11 - Find inverse [2 -6 1 -2] - Chapter 3 Matrices

Ex 3.4, 11 - Chapter 3 Class 12 Matrices - Part 2
Ex 3.4, 11 - Chapter 3 Class 12 Matrices - Part 3


Transcript

Ex 3.4, 11 Find the inverse of each of the matrices, if it exists.[■8(2&−[email protected]&−2)] Let A =[■8(2&−[email protected]&−2)] We know that A = IA [■8(2&−[email protected]&−2)] = A [■8(1&[email protected]&1)] R1 → R1 – R2 [■8(𝟐−𝟏&−6−(−2)@1&−2)] = [■8(1−0&0−[email protected]&1)] A [■8(𝟏&−[email protected]&−2)] = [■8(1&−[email protected]&1)] A R2 → R2 – R1 [■8(1&−[email protected]𝟏−𝟏&−2−(−4))] = [■8(1&−[email protected]−1&1−(−1))] A [■8(1&−[email protected]𝟎&2)] = [■8(1&−[email protected]−1&2)] A R2 → 1/2 R2 [■8(1&−[email protected]𝟎/𝟐&2/2)] = [■8(1&−[email protected](−1)/2&2/2)] A [■8(1&−[email protected]𝟎&1)] = [■8(1&−[email protected](−1)/2&1)] A R1 → R1 + 4R2 [■8(1+4(0)&−𝟒+𝟒(𝟏)@0&1)] = [■8(1+4((−1)/2)&−1+4(1)@(−1)/2&1)] A [■8(1&𝟎@0&1)] = [■8(−1&[email protected](−1)/2&1)] A I = [■8(−1&[email protected](−1)/2&1)] A This is similar to I = A-1A Thus, A-1 = [■8(−𝟏&𝟑@(−𝟏)/𝟐&𝟏)]

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.