Edexcel FP2 2016 June — Question 3 7 marks

Exam BoardEdexcel
ModuleFP2 (Further Pure Mathematics 2)
Year2016
SessionJune
Marks7
PaperDownload PDF ↗
TopicComplex numbers 2
TypeDirect nth roots: general complex RHS
DifficultyStandard +0.3 This is a standard FP2 question on finding nth roots of complex numbers. Students must convert to modulus-argument form, apply De Moivre's theorem to find all four roots, and plot them. While it requires multiple steps (finding r and θ, dividing argument by 4, adding 2πk/4 for k=0,1,2,3), this is a routine textbook exercise with well-practiced techniques. The Argand diagram part is straightforward once roots are found. Slightly easier than average A-level due to its mechanical nature.
Spec4.02k Argand diagrams: geometric interpretation4.02q De Moivre's theorem: multiple angle formulae4.02r nth roots: of complex numbers

3. (a) Find the four roots of the equation \(z ^ { 4 } = 8 ( \sqrt { 3 } + \mathrm { i } )\) in the form \(z = r \mathrm { e } ^ { \mathrm { i } \theta }\) (b) Show these roots on an Argand diagram.

3. (a) Find the four roots of the equation $z ^ { 4 } = 8 ( \sqrt { 3 } + \mathrm { i } )$ in the form $z = r \mathrm { e } ^ { \mathrm { i } \theta }$\\
(b) Show these roots on an Argand diagram.\\

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\hfill \mbox{\textit{Edexcel FP2 2016 Q3 [7]}}