Let $A_{nn}f{I}_{nm}($identity matrix$)$ nad $A^2=A,$ then

Novert arwwert

Monertice el $100$

Bas

Gokion

a$.$ Ais diagonatirabie rivirix

b Irace$(N)-(n+1)$

e Rark$($N$)n$

d$.$ Nl cigorwalues of A are necersiarily zero