Complex Numbers And Quadratic Equations question 420
Question: $ {{{ \frac{2i}{1+i} }}^{2}}= $ [BIT Ranchi 1992]
Options:
A) 1
B) $ 2i $
C) $ \alpha -i\beta (\alpha ,\beta \text{real),} $
D) $ ( \frac{3-4ix}{3+4ix} )= $
Show Answer
Answer:
Correct Answer: B
Solution:
$ {{[ \frac{2i}{1+i} ]}^{2}}={{[ ( \frac{2i}{1+i} )( \frac{1-i}{1-i} ) ]}^{2}}={{(i+1)}^{2}}=i^{2}+1+2i=2i $ .
BETA
