Question 0810

Maclaurin Series
2010 Paper 1 Question 2 Variant

Question

(i)
Find the first three terms of the Maclaurin series for
e2xcos5x.\mathrm{e}^{2 x} \cos 5 x.
[Your may use standard results given in the List of Formulae (MF26).]
[3]
(ii)
It is given that the first two terms of this series are equal to the first two terms in the series expansion, in ascending powers of x,{x,} or (1+252x)n.{(1 + \frac{25}{2} x)^n.} Find n{n} and show that the third terms in each of these series are equal.
[3]

Answer