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AP EAMCET · Maths · Matrices

Let \(a, b \in \mathbf{R}-\{0\}\), and \(I_2\) be the identity matrix of order 2. Then the rank of the (block) matrix \(\left[\begin{array}{ll}a I_2 & b_2 \\ a I_2 & b I_2\end{array}\right]\) is

  1. A 2
  2. B 1
  3. C 4
  4. D 3
Verified Solution

Answer & Solution

Correct Answer

(A) 2

Step-by-step Solution

Detailed explanation

Since \(a, b \in \mathbf{R}-\{0\}\) and \(I_2\) is a identify matrix of order 2 . Then the block matrix \(\left[\begin{array}{ll}a I_2 & b I_2 \\ a I_2 & b I_2\end{array}\right]\) is a non-singular matrix, so the rank of the given block matrix is 2.