Complex Numbers And Quadratic Equations question 830
Question: $ \frac{1-i}{1+i} $ is equal to [RPET 1984]
Options:
A) $ \cos \frac{\pi }{2}+i\sin \frac{\pi }{2} $
B) $ \cos \frac{\pi }{2}-i\sin \frac{\pi }{2} $
C) $ \sin \frac{\pi }{2}+i\cos \frac{\pi }{2} $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
$ \frac{1-i}{1+i}=\frac{(1-i)(1-i)}{(1+i)(1-i)}=\frac{1+{{(i)}^{2}}-2i}{1+1}=-i $ which can be written as $ \cos \frac{\pi }{2}-i $ $ \sin \frac{\pi }{2} $
BETA
