Complex Numbers And Quadratic Equations question 120

Question: The sum of amplitude of z and another complex number is $ \pi $ . The other complex number can be written[Orissa JEE 2004]

Options:

A) $ \bar{z} $

B) $ -\overline{z} $

C) z

D) $ -z $

Show Answer

Answer:

Correct Answer: B

Solution:

We have $ z=x+iy $ and let their complex $ z_2 $ and given that $ arg\ (z)+z_2=\pi $ $ z_2=\pi -arg(z) $ ; $ z_2=\pi +[ -{{\tan }^{-1}}\frac{y}{x} ] $ $ z_2=\pi +[arg\ (\bar{z})] $ which lies in second quadrant, i.e. $ -\bar{z} $ .