OCR FP3 — Question 1 4 marks

Exam BoardOCR
ModuleFP3 (Further Pure Mathematics 3)
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicComplex numbers 2
TypeDirect nth roots: find and express roots
DifficultyStandard +0.8 This is a Further Pure question requiring conversion to polar form, application of de Moivre's theorem for roots, and careful angle arithmetic to find three distinct cube roots. While the technique is standard for FP3, it requires multiple steps (finding modulus, argument, applying root formula, finding all three roots) and precision with angles, making it moderately challenging but still a routine application of complex number theory.
Spec4.02a Complex numbers: real/imaginary parts, modulus, argument4.02b Express complex numbers: cartesian and modulus-argument forms4.02r nth roots: of complex numbers

Find the cube roots of \(\frac{1}{2}\sqrt{3} + \frac{1}{2}i\), giving your answers in the form \(\cos \theta + i \sin \theta\), where \(0 \leqslant \theta < 2\pi\). [4]

Find the cube roots of $\frac{1}{2}\sqrt{3} + \frac{1}{2}i$, giving your answers in the form $\cos \theta + i \sin \theta$, where $0 \leqslant \theta < 2\pi$. [4]

\hfill \mbox{\textit{OCR FP3  Q1 [4]}}