Question 0814

Maclaurin Series
2014 Paper 1 Question 8 Variant

Question

It is given that
f(x)=181x2,f(x) = \frac{1}{81-x^2},
where 9<x<9.{-9 < x < 9.}
(i)
Write down f(x)  dx.{\displaystyle \int f(x) \; \mathrm{d}x.}
[1]
(ii)
Find the binomial expansion for f(x),{f(x),} up to and including the term in x6.{x^6.} Give the coefficients as exact fractions in their simplest form.
[4]
(iii)
Hence, or otherwise, find the first four non-zero terms of the Maclaurin series for ln(9+x9x).{\ln \left( \frac{9+x}{9-x} \right).} Give the coefficients as exact fractions in their simplest form.
[4]

Answer