Question 3 - Properties of Determinant - Chapter 4 Class 12 Determinants

Last updated at April 16, 2024 by

Ex 4.2, 3 - Prove using property |2 7 65 3 8 75 5 9 86| = 0

Ex 4.2, 3 - Chapter 4 Class 12 Determinants - Part 2

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Question 3 Using the property of determinants and without expanding, prove that: |■8(2&7&65@3&8&75@5&9&86)| = 0 |■8(2&7&65@3&8&75@5&9&86)| Applying C3 → C3 − C1 = |■8(2&7&𝟔𝟓−𝟐@3&8&𝟕𝟓−𝟑@5&9&𝟖𝟔−𝟓)| = |■8(2&7&63@3&8&72@5&9&81)| Rough 65 – 2 = 63, 63/7 = 9 75 – 3 = 72, 72/8 = 9 86 – 5 = 81, 81/9 = 9 = |■8(2&7&𝟗 × 7@3&8&𝟗 ×8@5&9&𝟗 × 9)| Taking out 9 common from C3 = 9 |■8(2&𝟕&𝟕@3&𝟖&𝟖@5&𝟗&𝟗)| Here, C2 and C3 are identical = 9 × 0 = 0 Thus, |■8(2&7&65@3&8&75@5&9&86)| = 0 Hence proved Using Property: If any two row or column are identical, then value of determinant is zero

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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