Find the 4th term from the beginning and end in the expansion of .

To Find :


I. 4th term from the beginning


II. 4th term from the end


Formulae :




For ,


, and n=9


As n=n ,therefore there will be total (n+1) terms in the expansion


Therefore,


I. For the 4th term from the starting.


We have a formula,



For t4 , r=3







Therefore, a 4th term from the starting


Now,


II. For the 4th term from the end


We have a formula,



For t(n-2) , r = (n-2)-1 = (n-3)




……….




Therefore, a 4th term from the end


Conclusion :


I. 4th term from the beginning


II. 4th term from the end


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