Moderate -0.5 This is a straightforward 3×3 determinant calculation with a parameter, requiring application of the standard formula (cofactor expansion or rule of Sarrus). While it involves algebraic manipulation with the parameter 'a', it's a routine Further Maths exercise with no conceptual difficulty beyond the mechanical process.
1 Find the determinant of the matrix $\left( \begin{array} { r r r } a & 4 & - 1 \\ 3 & a & 2 \\ a & 1 & 1 \end{array} \right)$.
\hfill \mbox{\textit{OCR FP1 2014 Q1 [3]}}