Challenging +1.2 This requires computing derivatives of a product from first principles (product rule, chain rule) and evaluating at x=0, which is more involved than standard Maclaurin series recall. However, it only asks for terms up to x², limiting the algebraic complexity, and the technique is straightforward application of the definition rather than requiring novel insight.
1 Find the Maclaurin's series for $e ^ { x } \tan x$ from first principles up to and including the term in $x ^ { 2 }$.\\
\hfill \mbox{\textit{CAIE Further Paper 2 2021 Q1 [5]}}