Ex 3.2

Chapter 3 Class 12 Matrices
Serial order wise

### Transcript

Ex 3.2, 1 Let A = [■8(2&4@3&2)], B = [■8(1&3@−2&5)], C = [■8(−2&5@3&4)] Find each of the following (i) A + B A + B = [■8(2&4@3&2)] + [■8( 1&3@−2&5)] = [■8(2+1&4+3@3−2&2+5)] = [■8(𝟑&𝟕@𝟏&𝟕)] Ex 3.2,1 Let A = [■8(2&4@3&2)], B = [■8(1&3@−2&5)], C = [■8(−2&5@3&4)] Find each of the following (ii) A – B A – B = [■8(2&4@3&2)]− [■8( 1&3@−2&5)] = [■8(2−1&4−3@3−(−2)&2−5)] = [■8(1&1@3+2&−3)] = [■8(𝟏&𝟏@𝟓&−𝟑)] Ex 3.2, 1 Let A = [■8(2&4@3&2)], B = [■8(1&3@−2&5)], C = [■8(−2&5@3&4)] Find each of the following 3A – C Finding 3A 3A = 3[■8(2&4@3&2)] = [■8(3 × 2&3 × 4@3 × 3 &3 × 2)] = [■8(𝟔&𝟏𝟐@𝟗&𝟔)] Hence 3A – C = [■8(6&12@9&6)] ⤶7− [■8(−2&5@3&4)] = [■8(6−(−2)&12−5@9−3&6−4)] = [■8(6+2&7@6&2)] = [■8(𝟖&𝟕@𝟔&𝟐)] Ex 3.2, 1 Let A = [■8(2&4@3&2)] B = [■8(1&3@−2&5)] , C = [■8(−2&5@3&4)]. Find each of the following (iv)AB AB = [■8(2&4@3&2)] [■8(1&3@−2&5)] = [■8(2 × 1+4 × −2 &2 × 3+4 × 5@3 × 1+2 × −2&3 × 3+2 × 5)] = [■8(2−8&6+20@3−4&9+10)] = [■8(−𝟔&𝟐𝟔@−𝟏&𝟏𝟗)] Ex 3.2, 1 Let A = [■8(2&4@3&2)] B = [■8(1&3@−2&5)] , C = [■8(−2&5@3&4)]. Find each of the following (v) BA BA = [■8(1&3@−2&5)] [■8(2&4@3&2)] = [■8(1 × 2+3 × 3 &1 × 4+3 × 2@−2 × 2+5 × 3&−2 × 4+5 × 2)] = [■8(2+9&4+6@−4+15&−8+10)] = [■8(𝟏𝟏&𝟏𝟎@𝟏𝟏&𝟐)]

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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 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.