C 154 ] 



Then i. By fubftituting/? — i >nfteadof«in the above cxprefllort 



■3 - - 



we have K^ = J 



+ n — 2. n- 

 - «— 3- «— 4 



n — m X I 



+ n—\. »— 5 

 &c. - &c. 



therefore 



f + n — 2. w — 3 



I — n — 3 n — 4 - 



v—y: = »2— I X -> ^ 



j + «— 4. «— 5 



^ &c. &c. 

 But by fubftituting n—z and «— i refpeaivery inftead of n, and 

 ?« — I inftead of m we have 



rj^ «_3. 72—4 - X I r+ "— ^- "—3 - X I 



H = <|-«— 4.W— 5 - X 7M— I and K = < -«— 3 «— 4 * x » 



( &c. &c. C. &c. &c. 



or H + K xm^i = L^— K^ or L^ = ^=T x H+K + K\ 



2. Taking a = « the expreflion becomes 



m — I 



Which 



