OCR MEI FP1 2006 January — Question 4 5 marks

Exam BoardOCR MEI
ModuleFP1 (Further Pure Mathematics 1)
Year2006
SessionJanuary
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMatrices
TypeConditions for unique solution
DifficultyModerate -0.8 This is a straightforward question testing basic matrix concepts: converting matrix equations to simultaneous equations and calculating a 2×2 determinant. The interpretation of zero determinant (no unique solution) is standard bookwork. While it's Further Maths content, these are foundational skills with minimal problem-solving required.
Spec4.03h Determinant 2x2: calculation4.03l Singular/non-singular matrices4.03r Solve simultaneous equations: using inverse matrix

4 The matrix equation \(\left( \begin{array} { r r } 6 & - 2 \\ - 3 & 1 \end{array} \right) \binom { x } { y } = \binom { a } { b }\) represents two simultaneous linear equations in \(x\) and \(y\).
  1. Write down the two equations.
  2. Evaluate the determinant of \(\left( \begin{array} { r r } 6 & - 2 \\ - 3 & 1 \end{array} \right)\). What does this value tell you about the solution of the equations in part (i)?

Question 4:
(i)
AnswerMarks
\(6x - 2y = a\)B1
\(-3x + y = b\)B1
(ii)
AnswerMarks Guidance
\(\det = (6)(1) - (-2)(-3) = 6 - 6 = 0\)M1 A1
The determinant is zero, so the matrix is singular and the equations do not have a unique solution — either no solution or infinitely many solutionsA1 must relate to equations
# Question 4:

**(i)**

$6x - 2y = a$ | B1 |

$-3x + y = b$ | B1 |

**(ii)**

$\det = (6)(1) - (-2)(-3) = 6 - 6 = 0$ | M1 A1 |

The determinant is zero, so the matrix is singular and the equations do not have a unique solution — either no solution or infinitely many solutions | A1 | must relate to equations

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4 The matrix equation $\left( \begin{array} { r r } 6 & - 2 \\ - 3 & 1 \end{array} \right) \binom { x } { y } = \binom { a } { b }$ represents two simultaneous linear equations in $x$ and $y$.\\
(i) Write down the two equations.\\
(ii) Evaluate the determinant of $\left( \begin{array} { r r } 6 & - 2 \\ - 3 & 1 \end{array} \right)$.

What does this value tell you about the solution of the equations in part (i)?

\hfill \mbox{\textit{OCR MEI FP1 2006 Q4 [5]}}