please explain the line in ex 3 - on comparing the indices of x in x2 and tr+1 , we obtain r=4.........

Dear Student!

Here is the answer to your query.

Suppose *x*^{2} occurs in the (*r + *1)^{th }term of the exposition

Comparing the indices or power of *x *in *x*^{2} and T_{r + 1} we obtain

Thus *x*^{2} occurs in (4 + 1)^{th }term = 5^{th} term

and its coefficient in the expansion of is given by

Cheers!

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