Question

If $1 - i$ is a complex number, then.

• A. $0 + 0i$
• B. $- 1 - i$
• C. $- 1 + i$
• D. None of these

Answer 1

Answer: (A)

$0 + 0i$

Answer 2

If $a = 1,b = 0$. Let $\frac{1 + b + ia}{1 + b - ia} = \frac{1 + i}{1 - i} = i$ ⇒ $\frac{3 + 2i\sin\theta}{1 - 2i\sin\theta}$

Re(z)= 0 ⇒ $\frac{3 - 4\sin^{2}\theta}{1 + 4\sin^{2}\theta} = 0$. Therefore $3 - 4\sin^{2}\theta = 0$

Thus $\theta$.