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Misc 14 - If matrix A is both symmetric and skew symmetric

Misc. 14 - Chapter 3 Class 12 Matrices - Part 2
Misc. 14 - Chapter 3 Class 12 Matrices - Part 3
Misc. 14 - Chapter 3 Class 12 Matrices - Part 4

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Misc 14 (Introduction) If the matrix A is both symmetric and skew symmetric, then A. A is a diagonal matrix B. A is a zero matrix C. A is a square matrix D. None of these Diagonal Matrix: Matrix with all non-diagonal elements zero. Eg: [■8(1&0&0@0&−2&0@0&0&4)] , [■8(−9&0@0&35)] Zero Matrix: Matrix with all elements zero Eg: [■8(0&0&0@0&0&0@0&0&0)] , [■8(0&0@0&0)] Square matrix Matrix with number of rows = Number of columns Eg: [■8(6&−2&2@−2&3&−1@2&−1&3)] , [■8(1&6@5&7)] Misc 14 If the matrix A is both symmetric and skew symmetric, then A. A is a diagonal matrix B. A is a zero matrix C. A is a square matrix D. None of these Since A is both symmetric and skew-symmetric matrix, A’ = A and A’ = –A Comparing both equations A = − A A + A = O 2A = O A = O Therefore, A is a zero matrix. So, B is the correct answer

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.