If find k such that A2 = kA – 2I2.

Given:


I2 is an identity matrix of size 2, so


Also given,


Now, we will find the matrix for A2, we get




[as cij = ai1b1j + ai2b2j + … + ainbnj]




Now, we will find the matrix for kA, we get





So,



Substitute corresponding values from eqn(i) and (ii), we get




[as rij = aij + bij + cij],


And to satisfy the above condition of equality, the corresponding entries of the matrices should be equal


Hence,


Therefore, the value of k is 1


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