CAIE P1 2010 November — Question 8 7 marks

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2010
SessionNovember
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStraight Lines & Coordinate Geometry
TypeLine and curve intersection
DifficultyModerate -0.3 This is a straightforward line-curve intersection problem requiring setting equations equal, solving a quadratic, then applying distance and midpoint formulas. All techniques are standard AS-level procedures with no novel insight needed, making it slightly easier than average but not trivial due to the algebraic manipulation involved.
Spec1.02c Simultaneous equations: two variables by elimination and substitution1.10c Magnitude and direction: of vectors

8 \includegraphics[max width=\textwidth, alt={}, center]{ae57d8f1-5a0d-426c-952d-e8b99c6aeaba-3_613_897_1311_623} The diagram shows part of the curve \(y = \frac { 2 } { 1 - x }\) and the line \(y = 3 x + 4\). The curve and the line meet at points \(A\) and \(B\).
  1. Find the coordinates of \(A\) and \(B\).
  2. Find the length of the line \(A B\) and the coordinates of the mid-point of \(A B\).

Question 8:
Part (i)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(3x^2 + x - 2 = 0\)M1A1 Eliminates \(x\) or \(y\); sets quadratic to 0
\((x+1)(3x-2) \rightarrow x = -1\) or \(\frac{2}{3}\)M1 Attempt to solve their equation
\((-1,\ 1),\ (\frac{2}{3},\ 6)\)A1 co
Part (ii)
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(AB^2 = (5/3)^2 + 5^2\)M1 \(\sqrt{}\) their coordinates from (i)
\(AB = 5.27(0\ldots)\)A1 Or \((5\sqrt{10})/3\) oe
mid-point \(= (-1/6,\ 7/2)\)B1\(\sqrt{}\) ft from their (i)
## Question 8:

**Part (i)**

| Answer/Working | Marks | Guidance |
|---|---|---|
| $3x^2 + x - 2 = 0$ | M1A1 | Eliminates $x$ or $y$; sets quadratic to 0 |
| $(x+1)(3x-2) \rightarrow x = -1$ or $\frac{2}{3}$ | M1 | Attempt to solve their equation |
| $(-1,\ 1),\ (\frac{2}{3},\ 6)$ | A1 | co |

**Part (ii)**

| Answer/Working | Marks | Guidance |
|---|---|---|
| $AB^2 = (5/3)^2 + 5^2$ | M1 | $\sqrt{}$ their coordinates from (i) |
| $AB = 5.27(0\ldots)$ | A1 | Or $(5\sqrt{10})/3$ oe |
| mid-point $= (-1/6,\ 7/2)$ | B1$\sqrt{}$ | ft from their (i) |

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8\\
\includegraphics[max width=\textwidth, alt={}, center]{ae57d8f1-5a0d-426c-952d-e8b99c6aeaba-3_613_897_1311_623}

The diagram shows part of the curve $y = \frac { 2 } { 1 - x }$ and the line $y = 3 x + 4$. The curve and the line meet at points $A$ and $B$.\\
(i) Find the coordinates of $A$ and $B$.\\
(ii) Find the length of the line $A B$ and the coordinates of the mid-point of $A B$.

\hfill \mbox{\textit{CAIE P1 2010 Q8 [7]}}