Symmetric and Skew-Symmetric Matrices

IMPORTANT

Symmetric and Skew-Symmetric Matrices: Overview

This topic covers concepts such as Symmetric and Skew-symmetric Matrices, Symmetric Matrix, Properties of Symmetric Matrices, Properties of Skew-Symmetric Matrices, Square Matrix as a Sum of Symmetric and Skew-Symmetric Matrices, etc.

Important Questions on Symmetric and Skew-Symmetric Matrices

EASY
IMPORTANT

Let A and B be symmetric matrices of same order, then which one of the following is correct regarding AB-BA?

1. Its diagonal entries are equal but nonzero

2. The sum of its non-diagonal entries is zero

Select the correct answer using the code given below :

EASY
IMPORTANT

If A=211-102013 then A-AT is

MEDIUM
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If x, y are any two non-zero real numbers, aij=xj+yi,A=aijn×n and P, Q are two n×n matrices such that A=x P+y Q then

EASY
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Determinant of skew-symmetric matrix of order "three" is always

HARD
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Let A and B be 3×3 symmetric matrices such that X=AB+BA and Y=AB-BA. Then [XYT is equal to XYT is the transpose of matrix XY.]

HARD
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Let A & B be 3×3 symmetric matrices such that  X=AB+BA and Y=AB-BA. Then (XY)T is equal to [(XY)T is the transpose of matrix XY.]

HARD
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If A and B are non-singular square matrices of even order such that AT=A, BT=-B and AB+BA=O

(where O is a null matrix ), then

HARD
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A is a 3×3 matrix with entries from the set -1,0,1. Then the probability that A is neither symmetric nor skew-symmetric is

HARD
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If A is a skew symmetric matrix of order 2 and B,C are matrices 1429, 9-4-2   1, then A3BC+A5B2C2+A7B3C3+..A2017B1009C1009 is

MEDIUM
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If A is skew symmetric matrix such that A2-I=0 then order of A is :-

EASY
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If A is skew symmetric matrix such that A2-I=0 then order of A is :-

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Let f(x)=lnx+x2+1, then the value of determinant fsin2017πfsinπ6fexfcos2π3fcos2017π2ftanπ3f-exfcot5π6f(0) is

MEDIUM
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If the matrix A is both symmetric and skew symmetric, then

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Which of the following option is correct for Xm, if X is a symmetric matrix and m is any natural number.

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What type of matrix would 12(X-X') be, if X is a square matrix and X' is the transpose of X.

EASY
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If A and B are non singular square matrices of even order such that A=A and B=-B and AB+BA=O (where O is null matrix), then choose appropriate option

HARD
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Let A be the set of all 4×4 skew symmetric matrices, whose entries are -1,0 or 1. If there are exactly four 0's, six 1'sand six -1's, then what will be the number of such matrices?

EASY
IMPORTANT

The trace of a 5×5 skew symmetric matrix is equal to:

HARD
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If A and B are any two 3 × 3  matrices such that A is a symmetric and B is a skew symmetric matrix, then the matrix AB-BA is

EASY
IMPORTANT

If a square matrix A=    2  03   4  3   15  7   2  is expressed as the sum of a symmetric and skew-symmetric matrix, then the symmetric matrix will be