Edexcel F1 2024 June — Question 6 9 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2024
SessionJune
Marks9
PaperDownload PDF ↗
TopicProof by induction
TypeProve matrix power formula
DifficultyStandard +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.
Spec4.01a Mathematical induction: construct proofs4.03c Matrix multiplication: properties (associative, not commutative)4.03i Determinant: area scale factor and orientation

  1. (a) Prove by induction that for \(n \in \mathbb { Z } ^ { + }\)
$$\left( \begin{array} { l l } 1 & r \\ 0 & 2 \end{array} \right) ^ { n } = \left( \begin{array} { c c } 1 & \left( 2 ^ { n } - 1 \right) r \\ 0 & 2 ^ { n } \end{array} \right)$$ 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 \(S\)

\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]}}