Just use the definition. You want to check that the inverse of [tex]I_n[/tex] is [tex]I_n[/tex] itself (this is just another way of saying [tex]I_n^{-1}=I_n[/tex]). What it comes down to is that [tex]I_nI_n=I_n[/tex].yes In is the inverese of In because In^-1 is the inverse of In and In^-1=In
true?