Past Papers’ Solutions | Cambridge International Examinations (CIE) | AS & A level | Mathematics 9709 | Pure Mathematics 1 (P1-9709/01) | Year 2010 | May-Jun | (P1-9709/11) | Q#2

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Question


i.       
Find the first 3 terms in the expansion of  in descending powers of .

   ii.       Hence find the coefficient of  in the expansion of .

Solution


i.
 

First rewrite the given expression in standard form.

Expression for the Binomial expansion of  is:

In the given case:

Hence;


ii.
 

To find the value of   in the expansion of

First we know from (i) that

Therefore:

Therefore coefficient of variable :

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