Complex transformations and mappings

A question is this type if and only if it involves a transformation w = f(z) mapping loci from the z-plane to the w-plane, requiring finding the image locus equation.

28 questions · Standard +1.0

4.02k Argand diagrams: geometric interpretation
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Edexcel FP2 Q22
10 marks Standard +0.8
    1. On the same Argand diagram sketch the loci given by the following equations. $$|z - 1| = 1,$$ $$\arg(z + 1) = \frac{\pi}{12},$$ $$\arg(z + 1) = \frac{\pi}{2}.$$ [4]
    2. Shade on your diagram the region for which $$|z - 1| \leq 1 \quad \text{and} \quad \frac{\pi}{12} \leq \arg(z + 1) \leq \frac{\pi}{2}.$$ [1]
    1. Show that the transformation $$w = \frac{z - 1}{z}, \quad z \neq 0,$$ maps \(|z - 1| = 1\) in the \(z\)-plane onto \(|w| = |w - 1|\) in the \(w\)-plane. [3] The region \(|z - 1| \leq 1\) in the \(z\)-plane is mapped onto the region \(T\) in the \(w\)-plane.
    2. Shade the region \(T\) on an Argand diagram. [2]
Edexcel FP2 Q46
11 marks Standard +0.3
A complex number \(z\) is represented by the point \(P\) in the Argand diagram. Given that $$|z - 3i| = 3,$$
  1. sketch the locus of \(P\). [2]
  2. Find the complex number \(z\) which satisfies both \(|z - 3i| = 3\) and \(\arg (z - 3i) = \frac{3}{4}\pi\). [4] The transformation \(T\) from the \(z\)-plane to the \(w\)-plane is given by $$w = \frac{2i}{w}.$$
  3. Show that \(T\) maps \(|z - 3i| = 3\) to a line in the \(w\)-plane, and give the cartesian equation of this line. [5]
WJEC Further Unit 1 Specimen Q7
9 marks Standard +0.3
The complex numbers \(z\) and \(w\) are represented, respectively, by points \(P(x, y)\) and \(Q(u,v)\) in Argand diagrams and $$w = z(1 + z)$$
  1. Show that $$v = y(1 + 2x)$$ and find an expression for \(u\) in terms of \(x\) and \(y\). [4]
  2. The point \(P\) moves along the line \(y = x + 1\). Find the Cartesian equation of the locus of \(Q\), giving your answer in the form \(v = au^2 + bu\), where \(a\) and \(b\) are constants whose values are to be determined. [5]