# 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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