Ex 4.1, 3 - Show that |2A| = 4|A|, if A = [1 2 4 2] - Finding determinant of a 2x2 matrix

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  1. Chapter 4 Class 12 Determinants
  2. Serial order wise

Transcript

Ex 4.1, 3 If A = 1 2 4 2 , then show that 2A = 4 A We need to prove 2A = 4 A Taking L.H.S 2A First calculating 2 A 2A = 2 1 2 4 2 = 2 1 2 2 2 4 2 2 = 2 4 8 4 So, 2 A = 2 4 8 4 = 2(4) 8 (4) = 8 32 = 24 Taking R.H.S 4 A As A = 1 2 4 2 So A = 1 2 4 2 = 1 (2) 4 (2) = 2 8 = 6 Hence, 4 A = 4 (2) = 24 = L.H.S L.H.S = R.H.S Hence proved

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Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.