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Question 1 - CBSE Class 12 Sample Paper for 2019 Boards - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at Dec. 16, 2024 by Teachoo

Question 1

If A and B are invertible matrices of order 3, |A| = 2, |(AB) -1 | = – 1/6. Find |B|

Transcript

Question 1 If A and B are invertible matrices of order 3, |𝐴| = 2, |(𝐴𝐵)^(−1) | = – 1/6 . Find |𝐵| Theory We know that A A-1 = I So, |A A-1| = |I| |A A-1| = 1 |A| |A-1| = 1 |A-1| = 1/|𝐴| Just for reference, no need to write Given |𝐴| = 2, |(𝐴𝐵)^(−1) | = – 1/6 We know that |(𝐴𝐵)^(−1) | = 1/(|𝐴𝐵|) |(𝐴𝐵)^(−1) | = 1/|𝐴||𝐵| −1/6 = 1/(2 × |𝐵| ) 2 × |𝐵| = –6 |𝐵| = (−6)/2 |𝑩| = – 3
  1. Class 12
  2. Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

    3. CBSE Class 12 Sample Paper for 2019 Boards

    CBSE Class 12 Sample Paper for 2018 Boards →
CBSE Class 12 Sample Paper for 2018 Boards →
Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

About the Author

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 and Computer Science at Teachoo