JEE Main 2024 Mathematics question
Let and B = I + adj(A) + (adj A)² + … + (adj A). Then, the sum of all the elements of the matrix B is:
Answer: (C)
Solution
adj A = [[1, −2], [0, 1]], so (adj A)ⁿ = [[1, −2n], [0, 1]] and B = [[11, −110], [0, 11]]; the sum of the elements is −88.