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Question

Mathematics Question on Algebra of Complex Numbers

The imaginary part of (1+i)2i(2i1)\frac{\left(1+i\right)^{2}}{i\left(2i-1\right)} is

A

45\frac{4}{5}

B

0

C

25\frac{2}{5}

D

45 - \frac{4}{5}

Answer

45 - \frac{4}{5}

Explanation

Solution

(1+i)2i(2i1)=1+i2+2i2i2i\frac{\left(1+i\right)^{2}}{i\left(2i-1\right)} = \frac{1+i^{2}+2i}{2i^{2} -i}
11+2i2i=2i2+i×(2i)(2i)=4i+2i24i2[i2=1]\Rightarrow \frac{1-1+2i}{-2-i} = - \frac{2i}{2+i}\times \frac{\left(2-i\right)}{\left(2-i\right)} = \frac{-4i +2i^{2}}{4-i^{2}} \left[\because i^{2 } = -1\right]
=4i24+1=24i5254i5= \frac{-4i-2}{4+1} = \frac{-2-4i}{5} \Rightarrow \frac{-2}{5} - \frac{4i}{5}
\therefore The imaginary part =45= - \frac{4}{5}