For A = [8(3 1 -1 2)], then 14 A −1 is given by

(a) 14 [8(2 -1 1 3)]    (b) [8(4 -2 2 6)]

(c) [8(2 -1 1 -3)]        (d) 2 [8(-3 -1 1 -2)]  

Ques 38 (MCQ) - For A = [ 3 1 −1 2 ], then 14A-1 is given by - Teachoo - CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)

part 2 - Question 38 - CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12
part 3 - Question 38 - CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards - Class 12

Share on WhatsApp

Transcript

Question 38 For A = [■8(3&1@−1&2)], then 14 A−1 is given by (a) 14 [■8(2&−1@1&3)] (b) [■8(4&−2@2&6)] (c) [■8(2&−1@1&−3)] (d) 2 [■8(−3&−1@1&−2)] We know that A-1 = 1/(|A|) adj A Now, |𝑨| = |■8(3&1@−1&2)| = 3 × 2 – (−1) × 1 = 6 + 1 = 7 So, the correct answer is (B) A =[■8(3&1@−1&2)] Now, adj A = [■8(3&1@−1&2)] = [■8(𝟐&−𝟏@𝟏&𝟑)] Thus, A-1 = 1/(|A|) adj A = 1/7 [■8(2&−1@1&3)] So, 14A-1 = 14 × 1/7 [■8(2&−1@1&3)] = 2 [■8(2&−1@1&3)] = [■8(2 × 2&2 × −1@2 × 1&2 × 3)] = [■8(𝟒&−𝟐@𝟐&𝟔)] So, the correct answer is (B)

Davneet Singh's photo - Co-founder, Teachoo

Made by

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