Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ex 4.4

Ex 4.4, 1

Ex 4.4, 2

Ex 4.4, 3 Important

Ex 4.4, 4 Important

Ex 4.4, 5

Ex 4.4, 6 Important

Ex 4.4, 7

Ex 4.4, 8

Ex 4.4, 9

Ex 4.4, 10 Important

Ex 4.4, 11 Important

Ex 4.4, 12

Ex 4.4, 13

Ex 4.4, 14 Important

Ex 4.4, 15 Important

Ex 4.4, 16

Ex 4.4, 17 (MCQ) Important You are here

Ex 4.4, 18 (MCQ) Important

Chapter 4 Class 12 Determinants

Serial order wise

Last updated at June 11, 2023 by Teachoo

Ex 4.4, 17 (Method 1) Let A be a nonsingular square matrix of order 3 × 3. Then |adj A| is equal to A. |A| B. |A|2 C. |A|3 D. 3 |A| We know that |𝑎𝑑𝑗 𝐴| = |𝐴|^(𝑛 − 1) where n is the order of Matrix A Here, n = 3 |𝑎𝑑𝑗 𝐴| = |𝐴|^(3 − 1) = |𝐴|^2 Hence, B is the correct answer Ex 4.4, 17 (Method 2) Let A be a nonsingular square matrix of order 3 × 3. Then |adj A| is equal to A. |A| B. |A|2 C. |A|3 D. 3 |A| We know that A (adj A) = |A|I Taking determinants both sides |A (ad jA)| = ||A|I| Solving |A (adj (A))| |A (adj (A))| = |A| |adj (A)| Solving ||A|I| ||A|I| = |A|3|I| = |A|3 Now, |A (ad jA)| = ||A|I| Putting values |A| |adj (A)| = |A|3 |adj (A)| = |A|3/|A| |adj (A)| = |A|2 Thus, B is the correct answer