Expression 2: "r" left parenthesis, "n" , right parenthesis equals sine left parenthesis, StartFraction, pi left parenthesis, "n" minus 2 , right parenthesis Over 2 "n" , EndFraction , right parenthesisrn=sinπn−22n
2
Expression 3: "r" left parenthesis, 3 , right parenthesisr3