Q75.If 𝐴= 2 -3 , then Adj3𝐴2 + 12𝐴 is equal to: -4 1 (1) 72 -84 (2) 51 63 -63 51 84 72 (3) 51 84 (4) 72 -63 63 72 -84 51
What This Question Tests
This problem tests the calculation of matrix powers, scalar multiplication, and the adjoint of a 2x2 matrix, requiring careful matrix algebra.
Concepts Tested
Formulas Used
A² = A * A
Adj(A) = (Cofactor matrix)^T
Adj(kA) = k^(n-1) Adj(A) for n x n matrix
For 2x2 matrix: A = [[a,b],[c,d]], Adj(A) = [[d,-b],[-c,a]]
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📋 Question Details
- Chapter
- Matrices
- Topic
- Adjoint of a matrix
- Year
- 2017
- Shift
- 02 Apr
- Q Number
- Q75
- Type
- MCQ
- NCERT Ref
- Class 12 Mathematics Ch 3: Matrices
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