IB skill practice

Apply de Moivre powers

Use de Moivre theorem to find a modulus or argument after a power.

Paper 1, Paper 2 5 marks Difficulty 4

Apply de Moivre powers - official syllabus scenario

For a coastal survey complex number \(z=4\operatorname{cis}(50^\circ)\), find the argument of \(z^4\) in degrees. Enter the requested value and choose the interpretation that matches the result.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.