Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Matrices

Question:

If A and B are symmetric matrices of the same order, then AB - BA is a:

Options:

symmetric matrix

zero matrix

skew symmetric matrix

identity matrix

Correct Answer:

skew symmetric matrix

Explanation:

The correct answer is Option (3) - skew symmetric matrix

$(AB-BA)^T$

$=(AB)^T-(BA)^T$

$=B^TA^T-A^TB^T$

$=BA-AB$

so $(AB-BA)^T=-(AB-BA)$

Hence its skew symmetric