Complex Numbers And Quadratic Equations question 228

Question: The value of i1/3 is [UPSEAT 2002]

Options:

A) $ \frac{\sqrt{3}+i}{2} $

B) $ \frac{\sqrt{3}-i}{2} $

C) $ \frac{1+i\sqrt{3}}{2} $

D) $ \frac{1-i\sqrt{3}}{2} $

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Answer:

Correct Answer: A

Solution:

$ {i^{1/3}}={{( \cos \frac{\pi }{2}+i\sin \frac{\pi }{2} )}^{1/3}}=\cos \frac{\pi }{6}+i\sin \frac{\pi }{6} $ $ =\frac{\sqrt{3}}{2}+\frac{i}{2} $ .