Question

if a is a square matrix such that a² = a, then write the value of 7a - (i + a)³ where i is an identity matrix.​

Answer 1

Answer:

given A2=A

7A−(I+A)3=7A−[I3+3A2I+3AI2+A3]

=7A−[I+3A+3A+A2.A]

=7A−[I+3A+3A+A]

=7A−I+7A

=−I

Answer 2

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