Let $\mathrm{f}(x)=2{{\mathrm{e}}^{x+1}}{{\cos }^{2}}(x)$. Find the series expansion of $\mathrm{f}(

Question

Let $\mathrm{f}(x)=2{{\mathrm{e}}^{x+1}}{{\cos }^{2}}(x)$. Find the series expansion of $\mathrm{f}(x)$ in ascending powers of $x$, up to and including the term in ${{x}^{3}}$. [You may use standard results given in the List of Formulae (MF26).] [4]

Accepted Answer

$\approx 2\mathrm{e}\left[ 1+x-\frac{1}{2}{{x}^{2}}-\frac{5}{6}{{x}^{3}} \right]$

IJC P1 Q6 (i)

IJC P1 Q6 (i)

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