Finding all complex solutions $z$ of an equation involving $z$ and its conjugate $\bar z$

complex numbers

I need to find all complex solutions of the equation: $2z + 2i\bar z = 0.$

This is what I have done so far:

Let $z = x + yi$ and $\bar z = x – yi$ and then substitute into the equation.

$2(x + yi) + 2i(x – yi) = 0$

$2x + 2yi + 2xi – 2yi^2 = 0$

$2x + 2yi + 2xi – 2y(-1) = 0$

$2x + 2yi + 2xi + 2y = 0$

$2x + 2y + 2yi + 2xi = 0$

$2(x + y) + 2(x + y)i = 0$

So now we setup the two equations which would be the same

$2(x + y) = 0$

$2(x + y) = 0$

When I checked the solutions to this on Wolfram Alpha it simply said $y = -x. $
Have I gone about this question the wrong way? What is the best way to approach this question and what are the correct solutions?

Best Answer

Your answer $2(x+y)=0\iff x+y=0$ is the same as Wolfram Alpha's $y=-x$.

You could have said $2(x+y)+2(x+y)i=0\iff 2(x+y)(1+i)=0\iff x+y=0$.

Related Question