Past Papers’ Solutions | Cambridge International Examinations (CIE) | AS & A level | Mathematics 9709 | Pure Mathematics 1 (P1-9709/01) | Year 2018 | May-Jun | (P1-9709/13) | Q#2

Hits: 432

Question

Find the coefficient of   in the expansion of .

Solution

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

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 terms with i.e. : we can  equate;

Now we can find the term with; Substituting ;

Hence the coefficient of  is .

Comments