A ray is drawn from the point \((-2, 1)\) at an angle of \(\frac{2\pi}{3}\) to the positive real axis direction. What is the equation of this subset in the form \(\text{Arg}(z - z_0) = \theta\)?
Specialist Mathematics Β· Unit 2 Β· Complex arithmetic and algebra Β· Subsets of the complex plane (the Argand plane)
Identify and sketch subsets of the complex plane determined by straight lines and circles, e.g. |π§ β 3π| < 4, π 4 β€ Arg(π§) β€ 3π 4, Re(π§) > Im(π§) and |π§ β 1| = 2|π§ β π|.
Practise this objective
AI-marked practice questions tied to QCAA mark schemes for this exact LO. Free to start.
Start free practicePractice questions for this objective
Full questions, answers and worked solutions unlock when you start a free practice session.
Consider the subset of the complex plane defined by \(|z - 2 - i| = 2|z + 1 - 2i|\) for \(z \in \mathbb{C}\). (a) By letting \(z = x + yi\) where \(x, y \in \mathbb{R}\), show that this equation can be written in the form \((x - h)^2 + (y - k)^2 = r^2\) and hence identify the geometric shape. (1 mark) (b) Determine the coordinates of the centre of this shape. (1 mark) (c) Calculate the radius of this shape, giving your answer in exact form. (1 mark)
Which statement correctly describes the subset of the complex plane represented by \(\text{Arg}(z - 2 - i) = \frac{2\pi}{3}\)?