How Do You Solve Complex Number Equations with Trigonometric Forms?

VADER25
Messages
6
Reaction score
0
hi, I am trying to solve this equation and i would like some help.
i've done some of it already and i don't know how to go on from here.

z=-\frac{(4-4i)(\sqrt{6}-i\sqrt{2})}{i}\\ =-\frac{(4-4i)(\sqrt{6}-i\sqrt{2})-i}{i(-i)}=(4i+4)(\sqrt{6}-i\sqrt{2})\\ \hspace{6} r=\sqrt{4^{2}+4^{2}}=\sqrt{32}\hspace{6} and \hspace{6} v=\frac{\pi }{4}\hspace{6}


the answer should be in this form a*pi/b
 
Last edited:
Physics news on Phys.org
It looks like you multiplied out (-i)(4-4i) incorrectly...?
 
VADER25 said:
hi, I am trying to solve this equation and i would like some help.
i've done some of it already and i don't know how to go on from here.

z=-\frac{(4-4i)(\sqrt{6}-i\sqrt{2})}{i}\\ =-\frac{(4-4i)(\sqrt{6}-i\sqrt{2})-i}{i(-i)}=(4i+4)(\sqrt{6}-i\sqrt{2})\\ \hspace{6} r=\sqrt{4^{2}+4^{2}}=\sqrt{32}\hspace{6} and \hspace{6} v=\frac{\pi }{4}\hspace{6}


the answer should be in this form a*pi/b
What exactly is the question then? You gave an expression of z and now you want the "argument" of z? Any complex number can be written in the form z= r(cos(\theta)+ i sin(\theta))= r e^{i\theta}.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top