Present value and future value of annuity-immediate and annuity-due. 

Prove the following identities : (1) (i) 1 (m) a nli m + i(m); 'nli 1 (ii) (m) 'nli 1 + d(m); (m) 'nli (iii) = [ + : ;(m) + m an]i: i(m)