OCR FP1 2007 June — Question 8 8 marks

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2007
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeRegion shading with multiple inequalities
DifficultyStandard +0.3 This is a straightforward Further Maths question requiring students to sketch standard loci (a circle and a half-line) and shade a region defined by simple inequalities. While it's from FP1, the techniques are routine: recognizing |z-a|=r as a circle and arg(z-a)=θ as a half-line, then correctly interpreting inequalities. No problem-solving insight or complex reasoning required, just careful application of standard methods.
Spec4.02o Loci in Argand diagram: circles, half-lines4.02p Set notation: for loci

8 The loci \(C _ { 1 }\) and \(C _ { 2 }\) are given by \(| z - 3 | = 3\) and arg \(( z - 1 ) = \frac { 1 } { 4 } \pi\) respectively.
  1. Sketch, on a single Argand diagram, the loci \(C _ { 1 }\) and \(C _ { 2 }\).
  2. Indicate, by shading, the region of the Argand diagram for which $$| z - 3 | \leqslant 3 \text { and } 0 \leqslant \arg ( z - 1 ) \leqslant \frac { 1 } { 4 } \pi$$

AnswerMarks Guidance
(i) Circle, centre \((3, 0)\), y-axis a tangent at origin. Straight line, through \((1, 0)\) with +ve slope. In 1st quadrant only.B1B1 B1 B1 B1 B2ft Sketch showing correct features. N.B. treat 2 diagrams as MR.
(ii) Inside circle, below line, above x-axis.
Total: 6 + 2 = 8 marks
(i) Circle, centre $(3, 0)$, y-axis a tangent at origin. Straight line, through $(1, 0)$ with +ve slope. In 1st quadrant only. | B1B1 B1 B1 B1 B2ft | Sketch showing correct features. N.B. treat 2 diagrams as MR. |

(ii) Inside circle, below line, above x-axis. | | |

**Total: 6 + 2 = 8 marks**
8 The loci $C _ { 1 }$ and $C _ { 2 }$ are given by $| z - 3 | = 3$ and arg $( z - 1 ) = \frac { 1 } { 4 } \pi$ respectively.\\
(i) Sketch, on a single Argand diagram, the loci $C _ { 1 }$ and $C _ { 2 }$.\\
(ii) Indicate, by shading, the region of the Argand diagram for which

$$| z - 3 | \leqslant 3 \text { and } 0 \leqslant \arg ( z - 1 ) \leqslant \frac { 1 } { 4 } \pi$$

\hfill \mbox{\textit{OCR FP1 2007 Q8 [8]}}