Expression 2: "A" left parenthesis, "i" , right parenthesis equals left parenthesis, cos left parenthesis, StartFraction, 2 pi Over "N" , EndFraction "i" , right parenthesis , sin left parenthesis, StartFraction, 2 pi Over "N" , EndFraction "i" , right parenthesis , right parenthesisAi=cos2πNi,sin2πNi