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Proof and induction — Question 25

Original QCE Vault practice · 1 mark

Q25 · Practice questionSimple familiar1 mark

QUESTION 25

Using De Moivre’s theorem, sin⁡(3x)=3sin⁡x−4sin⁡3x\sin(3x)=3\sin x-4\sin^3x. The coefficient of sin⁡3x\sin^3x is
(A)
44
(B)
−4-4
(C)
33
(D)
−3-3
Question linkSyllabus coverage

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