Question

If \(iz^4 + 1 = 0\) then \(z\) can take the value

• A. \(\cos \frac{\pi}{8} + i\sin \frac{\pi}{8}\)
• B. \(\cos \frac{\pi}{4} + i\sin \frac{\pi}{4}\)
• C. \(\cos \frac{3\pi}{8} + i\sin \frac{3\pi}{8}\)
• D. \(\cos \frac{\pi}{2} + i\sin \frac{\pi}{2}\)

Hint:

For \(z^n = r(\cos\theta + i\sin\theta)\), roots are \(\cos\frac{\theta+2k\pi}{n}\).

Answer 1

The Correct Option is B