Let A and B be two $3 \times 3$ non-zero real matrices such that AB is a zero matrix. Then
Solution
<p>AB is zero matrix</p>
<p>$\Rightarrow |A| = |B| = 0$</p>
<p>So neither A nor B is invertible</p>
<p>If $|A| = 0$</p>
<p>$\Rightarrow |\mathrm{adj}\,A| = 0$ so $\mathrm{adj}\,A$</p>
<p>$AX = 0$ is homogeneous system and $|A| = 0$</p>
<p>So, it is having infinitely many solutions</p>
About this question
Subject: Mathematics · Chapter: Matrices and Determinants · Topic: Types of Matrices and Operations
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