Complex numbers problems | Solving equations using polar form

AI Thread Summary
The discussion revolves around solving the complex equation |z| - z = 1 + 2i. Participants suggest using polar form and equating real and imaginary components after substituting |z| and z with their respective expressions. One user initially attempts a solution by assuming a value for y but struggles to progress. The solution to the equation is noted as 3/2 - 2i, highlighting the importance of using polar coordinates for complex number problems. The conversation emphasizes different methods for tackling complex equations, showcasing the utility of polar form in simplifying the process.
Broken Steel
Messages
4
Reaction score
0

Homework Statement


Solve the equation in the complex numbers set (this is as best as i could translate since English is not my native language :D)

\left|z\right|-z=1+2i


Homework Equations


|z|=sqrt{x^2+y^2}

z=x+iy

The Attempt at a Solution


Well i started by supposing y=1 and then i get sqrt{x^2+1}-x=1-i+x
i tried to square the whole equation but i end up with nothing.. So what should I do??

Oh and the solution is 3/2 - 2i
 
Physics news on Phys.org
Hi Broken Steel! :smile:

(have a square-root: √ and a phi: φ and try using the X2 tag just above the Reply box :wink:)

Hint: re :smile:
 
How about this way?
\left|z\right|-z=1+2i

Replace the |z| and z by the values you specified above:
\sqrt{x^2+y^2} - (x + yi) = 1 + 2i

Remove the parentheses, and then equate the real coefficients and the imaginary coefficients.
 
tiny-tim said:
Hi Broken Steel! :smile:

(have a square-root: √ and a phi: φ and try using the X2 tag just above the Reply box :wink:)

Hint: re :smile:


Likes this method because it is more useful for dealing with complex numbers.

Also, eumyang's is probably a more familiar method.
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Back
Top