ExamBro
ExamBro
CUET · MATHS · PYQ PAPER 2023

If \(A=\left[\begin{array}{cc}2 & -3 \\ 3 & 4\end{array}\right]\) then, the value of \(A^2-6 A\)

  1. A 6I, Where I is an identity matrix of order 2
  2. B 6I, Where I is an identity matrix of order 2
  3. C 17I, Where I is an identity matrix of order 2
  4. D \(-17 I\),, Where I is an identity matrix of order 2
Verified Solution

Answer & Solution

Correct Answer

(D) \(-17 I\),, Where I is an identity matrix of order 2

Step-by-step Solution

Detailed explanation

\( \text{tr}(A) = 2 + 4 = 6 \) \( \det(A) = (2)(4) - (-3)(3) = 8 + 9 = 17 \) \( A^2 - \text{tr}(A)A + \det(A)I = 0 \) \( A^2 - 6A + 17I = 0 \) \( A^2 - 6A = -17I \)