OCR FP1 2007 January — Question 4 6 marks

Exam BoardOCR
ModuleFP1 (Further Pure Mathematics 1)
Year2007
SessionJanuary
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex Numbers Argand & Loci
TypeRegion shading with multiple inequalities
DifficultyModerate -0.3 This is a straightforward Further Maths question requiring standard knowledge of loci in the complex plane. Part (i) asks for a circle with center (1,-1) and radius √2, while part (ii) requires shading an annulus. These are routine applications of the modulus-locus relationship with no problem-solving or novel insight required, making it slightly easier than average despite being Further Maths content.
Spec4.02k Argand diagrams: geometric interpretation4.02o Loci in Argand diagram: circles, half-lines

4
  1. Sketch, on an Argand diagram, the locus given by \(| z - 1 + \mathrm { i } | = \sqrt { 2 }\).
  2. Shade on your diagram the region given by \(1 \leqslant | z - 1 + \mathrm { i } | \leqslant \sqrt { 2 }\).

AnswerMarks Guidance
(i) CircleB1
Centre \((1, -1)\)B1
Passing through \((0, 0)\)B1 (3 marks)
(ii) Sketch a concentric circleB1
Inside (i) and touching axesB1
Shade between the circlesB1 (3 marks)
(i) Circle | B1 |

Centre $(1, -1)$ | B1 |

Passing through $(0, 0)$ | B1 | (3 marks)

(ii) Sketch a concentric circle | B1 |

Inside (i) and touching axes | B1 |

Shade between the circles | B1 | (3 marks)
4 (i) Sketch, on an Argand diagram, the locus given by $| z - 1 + \mathrm { i } | = \sqrt { 2 }$.\\
(ii) Shade on your diagram the region given by $1 \leqslant | z - 1 + \mathrm { i } | \leqslant \sqrt { 2 }$.

\hfill \mbox{\textit{OCR FP1 2007 Q4 [6]}}