Past Papers’ Solutions | Cambridge International Examinations (CIE) | AS & A level | Mathematics 9709 | Pure Mathematics 1 (P1-9709/01) | Year 2011 | Oct-Nov | (P1-9709/12) | Q#1
i. Find the first 3 terms in the expansion of , in ascending powers of .
ii. Use the result in part (i) to find the coefficient of in the expansion of .
First rewrite the given expression in standard form.
Expression for the Binomial expansion of is:
In the given case:
We can rearrange/rewrite as:
We know from (i) that
Hence the coefficient of variable is .