Determinants Matrices Question 93

Question: If $ A^{3}=0 $ , then I=A+ $ A^{2} $ equals

Options:

A) $ I-A $

B) $ {{(I+A^{1})}^{-1}} $

C) $ {{(I-A)}^{-1}} $

D) none of these

Show Answer

Answer:

Correct Answer: C

Solution:

  • [c] Given $ A^{3}=0 $ Now, $ (I-A)(I+A+A^{2}) $

$ =I^{2}+IA+IA^{2}-AI-A^{2}-A^{3} $

$ =I-A^{3}=I $
$ \Rightarrow {{(I-A)}^{-1}}=I+A+A^{2} $