AQA Further AS Paper 1 2018 June — Question 14

Exam BoardAQA
ModuleFurther AS Paper 1 (Further AS Paper 1)
Year2018
SessionJune
TopicComplex Numbers Argand & Loci

14
  1. Sketch, on the Argand diagram below, the locus of points satisfying the equation $$| z - 3 | = 2$$
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    14
  2. There is a unique complex number \(w\) that satisfies both $$| w - 3 | = 2 \quad \text { and } \quad \arg ( w + 1 ) = \alpha$$ where \(\alpha\) is a constant such that \(0 < \alpha < \pi\) 14
    1. Find the value of \(\alpha\).
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  3. (ii) Express \(w\) in the form \(r ( \cos \theta + \mathrm { i } \sin \theta )\).
    Give each of \(r\) and \(\theta\) to two significant figures.
    1. (a) Show that
    $$\frac { 1 } { r + 2 } - \frac { 1 } { r + 3 } = \frac { 1 } { ( r + 2 ) ( r + 3 ) }$$