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If A = [ 2 − 1 3 − 4 5 1 ] and B = ⎡ ⎢ ⎣ 2 3 4 − 2 1 5 ⎤ ⎥ ⎦ then - Mathematics

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Question

If  \[A = \begin{bmatrix}2 & - 1 & 3 \\ - 4 & 5 & 1\end{bmatrix}\text{ and B }= \begin{bmatrix}2 & 3 \\ 4 & - 2 \\ 1 & 5\end{bmatrix}\] then

Options

  • only AB is defined

  • only BA is defined

  • AB and BA both are defined

  • AB and BA both are not defined

MCQ

Solution

Given : 

\[A = \begin{bmatrix}2 & - 1 & 3 \\ - 4 & 5 & 1\end{bmatrix} \text{and B }= \begin{bmatrix}2 & 3 \\ 4 & - 2 \\ 1 & 5\end{bmatrix}\]

Order of A is 2 × 3 and order of B is 3 × 2.

Therefore, AB and BA both are defined.

Hence, the correct option is (c).

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Chapter 5: Algebra of Matrices - Exercise 5.7 [Page 69]

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RD Sharma Mathematics [English] Class 12
Chapter 5 Algebra of Matrices
Exercise 5.7 | Q 43 | Page 69

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