If $A^3 =O$, then $I + A+ A^2$ equals
Answer & explanation
Correct answer: option 2
We have,
$(I-A) (I + A+ A^2)=I+A+ A^2-A-A^2-A^3 = I-O =I$
$∴(I-A)^{-1}=I+ A+ A^2$
If $A^3 =O$, then $I + A+ A^2$ equals
Correct answer: option 2
We have,
$(I-A) (I + A+ A^2)=I+A+ A^2-A-A^2-A^3 = I-O =I$
$∴(I-A)^{-1}=I+ A+ A^2$