OCR MEI Further Pure Core 2022 June — Question 6 5 marks

Exam BoardOCR MEI
ModuleFurther Pure Core (Further Pure Core)
Year2022
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIntegration with Partial Fractions
TypeBasic partial fractions then integrate
DifficultyStandard +0.3 This is a standard matrix induction proof requiring verification of the base case (n=1) and inductive step. While it's a Further Maths topic, the structure is routine: multiply the matrices, simplify using the inductive hypothesis, and verify the result matches the required form. The matrix multiplication is straightforward with many zero entries, making calculations simpler than typical induction proofs.
Spec4.01a Mathematical induction: construct proofs4.03b Matrix operations: addition, multiplication, scalar

6 Prove by mathematical induction that \(\left( \begin{array} { r l } 2 & 0 \\ - 1 & 1 \end{array} \right) ^ { n } = \left( \begin{array} { c c } 2 ^ { n } & 0 \\ 1 - 2 ^ { n } & 1 \end{array} \right)\) for all positive integers \(n\). Answer all the questions.
Section B (107 marks)

Question 6:
AnswerMarks
62 0 2 0
( )=( ) so true when 𝑛 = 1
−1 1 1−2 1
[Assume true for 𝑛 = 𝑘]
2 0 𝑘+1 2𝑘 0 2 0
( ) = ( )( )
−1 1 1−2𝑘 1 −1 1
2𝑘+1 0
= ( )
2−2𝑘+1−1 1
2𝑘+1 0
= ( ) [so true for 𝑛 = 𝑘+1]
1−2𝑘+1 1
As true for 𝑛 = 1, and if true for 𝑛 = 𝑘 then true for
AnswerMarks
𝑛 = 𝑘+1, true for all nB1
M1
M1
A1
B1cao
AnswerMarks
[5]2.1
2.1
2.1
2.3
AnswerMarks
2.4Intermediate step seen
Must receive all 4 previous marks for this to be awarded
Question 6:
6 | 2 0 2 0
( )=( ) so true when 𝑛 = 1
−1 1 1−2 1
[Assume true for 𝑛 = 𝑘]
2 0 𝑘+1 2𝑘 0 2 0
( ) = ( )( )
−1 1 1−2𝑘 1 −1 1
2𝑘+1 0
= ( )
2−2𝑘+1−1 1
2𝑘+1 0
= ( ) [so true for 𝑛 = 𝑘+1]
1−2𝑘+1 1
As true for 𝑛 = 1, and if true for 𝑛 = 𝑘 then true for
𝑛 = 𝑘+1, true for all n | B1
M1
M1
A1
B1cao
[5] | 2.1
2.1
2.1
2.3
2.4 | Intermediate step seen
Must receive all 4 previous marks for this to be awarded
6 Prove by mathematical induction that $\left( \begin{array} { r l } 2 & 0 \\ - 1 & 1 \end{array} \right) ^ { n } = \left( \begin{array} { c c } 2 ^ { n } & 0 \\ 1 - 2 ^ { n } & 1 \end{array} \right)$ for all positive integers $n$.

Answer all the questions.\\
Section B (107 marks)

\hfill \mbox{\textit{OCR MEI Further Pure Core 2022 Q6 [5]}}