OCR C1 2005 January — Question 5 7 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Year2005
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeBasic factored form sketching
DifficultyEasy -1.2 This is a straightforward C1 curve sketching question requiring only basic recall of standard function shapes and simple factorization. Part (i) is a standard reciprocal graph, part (ii) requires factoring to find x-intercepts (0, ±1) with no calculus needed, and part (iii) is a reflected square root function. All three are textbook examples with no problem-solving or novel insight required.
Spec1.02n Sketch curves: simple equations including polynomials1.02o Sketch reciprocal curves: y=a/x and y=a/x^2

5 On separate diagrams,
  1. sketch the curve \(y = \frac { 1 } { x }\),
  2. sketch the curve \(y = x \left( x ^ { 2 } - 1 \right)\), stating the coordinates of the points where it crosses the \(x\)-axis,
  3. sketch the curve \(y = - \sqrt { } x\).

AnswerMarks Guidance
(i)Marks Guidance
Correct curve in \(+ve\) quadrantB1
in \(-ve\) quadrantB1 2
(ii)Marks Guidance
Positive cubic with clearly seen max and min pointsM1
\((-1.0), (0.0), (1.0)\)A1 Any one point stated or marked on sketch
A1 3Curve passes through all 3 points and no extras stated or marked on sketch
(iii)Marks Guidance
Graph only in bottom right hand quadrantB1
Correct graph, passing through originB1 2
7
**(i)** | **Marks** | **Guidance**
---|---|---
Correct curve in $+ve$ quadrant | B1 | 
in $-ve$ quadrant | B1 2 | 

**(ii)** | **Marks** | **Guidance**
---|---|---
Positive cubic with clearly seen max and min points | M1 | 
$(-1.0), (0.0), (1.0)$ | A1 | Any one point stated or marked on sketch
 | A1 3 | Curve passes through all 3 points and no extras stated or marked on sketch

**(iii)** | **Marks** | **Guidance**
---|---|---
Graph only in bottom right hand quadrant | B1 | 
Correct graph, passing through origin | B1 2 | 
| **7** |
5 On separate diagrams,\\
(i) sketch the curve $y = \frac { 1 } { x }$,\\
(ii) sketch the curve $y = x \left( x ^ { 2 } - 1 \right)$, stating the coordinates of the points where it crosses the $x$-axis,\\
(iii) sketch the curve $y = - \sqrt { } x$.

\hfill \mbox{\textit{OCR C1 2005 Q5 [7]}}