# Past Papers’ Solutions | Cambridge International Examinations (CIE) | AS & A level | Mathematics 9709 | Pure Mathematics 1 (P1-9709/01) | Year 2009 | Oct-Nov | (P1-9709/11) | Q#3

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**Question**

**
i. **Find the first three terms in the expansion of in ascending powers of .

**ii. **Given that the coefficient of in the expansion of is , find the value of the constant .

**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 term with in the expansion of

From (i) we have;

Therefore;

We are interested only in coefficient of which is equal to 48.,

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