# Thread: finding z1 , z2 of complex numer

1. ## finding z1 , z2 of complex numer

in order to get z1 and z2 , i tried to express z^2 into polar form, but z is to the power of 2, i'm not sure whether it can be epressed in polar form of not. by the way , here's my working. how should i proceed? i dont think my ans is correct.

2. ## Re: finding z1 , z2 of complex numer

Originally Posted by delso
in order to get z1 and z2 , i tried to express z^2 into polar form, but z is to the power of 2, i'm not sure whether it can be epressed in polar form of not. by the way , here's my working. how should i proceed? i dont think my ans is correct.
Please learn some basic LaTeX. It is hard enough to read from an image,
On top of that, why should we read your scratching?

3. ## Re: finding z1 , z2 of complex numer

$\text{Arg}(1-2\sqrt 2 i)=\arctan(-2 \sqrt 2)=\theta$

${z_1} = \sqrt 3 \exp \left( {\frac{\theta }{2} } \right)\;\& \;{z_2} = \sqrt 3 \exp \left( {\frac{\theta+\pi }{2 }} \right)$

4. ## Re: finding z1 , z2 of complex numer

Originally Posted by Plato
$\text{Arg}(1-2\sqrt 2 i)=\arctan(-2 \sqrt 2)=\theta$

${z_1} = \sqrt 3 \exp \left( {\frac{\theta }{2} } \right)\;\& \;{z_2} = \sqrt 3 \exp \left( {\frac{\theta+\pi }{2 }} \right)$
can you please show me how do u express z^2 in polar form step by step, i have done it in the very first post, but i dont think it's correct. my ans is weird. i cant understand your working in post 3