| Exam Board | Edexcel |
|---|---|
| Module | F1 (Further Pure Mathematics 1) |
| Year | 2024 |
| Session | June |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Topic | Proof by induction |
| Type | Prove matrix power formula |
| Difficulty | Standard +0.3 This is a standard Further Maths induction proof with routine matrix multiplication. Part (a) follows a textbook template for matrix induction (base case, inductive step with matrix multiplication). Parts (b) and (c) are straightforward applications: substituting r=-2 and n=4 into the proven formula, computing a matrix product, and using the determinant-area relationship. While it requires multiple techniques, each step is mechanical with no novel insight required. Slightly easier than average A-level due to its highly structured nature. |
| Spec | 4.01a Mathematical induction: construct proofs4.03c Matrix multiplication: properties (associative, not commutative)4.03i Determinant: area scale factor and orientation |
\begin{enumerate}
\item (a) Prove by induction that for $n \in \mathbb { Z } ^ { + }$
\end{enumerate}
$$\left( \begin{array} { l l }
1 & r \\
0 & 2
\end{array} \right) ^ { n } = \left( \begin{array} { c c }
1 & \left( 2 ^ { n } - 1 \right) r \\
0 & 2 ^ { n }
\end{array} \right)$$
where $r$ is a constant.
$$\mathbf { M } = \left( \begin{array} { l l }
4 & 0 \\
0 & 5
\end{array} \right) \quad \mathbf { N } = \left( \begin{array} { r r }
1 & - 2 \\
0 & 2
\end{array} \right) ^ { 4 }$$
The transformation represented by matrix $\mathbf { M }$ followed by the transformation represented by matrix $\mathbf { N }$ is represented by the matrix $\mathbf { B }$\\
(b) (i) Determine $\mathbf { N }$ in the form $\left( \begin{array} { l l } a & b \\ c & d \end{array} \right)$ where $a , b , c$ and $d$ are integers.\\
(ii) Determine B
Hexagon $S$ is transformed onto hexagon $S ^ { \prime }$ by matrix $\mathbf { B }$\\
(c) Given that the area of $S ^ { \prime }$ is 720 square units, determine the area of $S$
\hfill \mbox{\textit{Edexcel F1 2024 Q6 [9]}}