Past Papers’ Solutions | Cambridge International Examinations (CIE) | AS & A level | Mathematics 9709 | Pure Mathematics 1 (P1-9709/01) | Year 2019 | May-Jun | (P1-9709/12) | Q#1

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Question

Find the coefficient of x in the expansion of .

 

Solution

We are required to find the coefficient of in the expansion of given expression.

We are given expression as;

Expression for the general term in the Binomial expansion of is:

First rewrite the given expression in standard form.

In the given case:

Hence;

Since we are looking for the coefficient of : we can equate;

Now we can find the coefficient of; Substituting ;

Hence the coefficient of  is .

 

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