Sorry, I was having difficulty with the equation editor on here. I've attached my problem as a picture file.

I need to show that the two equations are equal, and I'm not sure where to begin.

Thanks!

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- Jan 20th 2010, 07:47 AMchemekydievariance problem (i think)
Sorry, I was having difficulty with the equation editor on here. I've attached my problem as a picture file.

I need to show that the two equations are equal, and I'm not sure where to begin.

Thanks! - Jan 20th 2010, 08:01 AMPlato
Assuming that $\displaystyle \overline{z}$ is the conjugate of the complex number $\displaystyle z$,

**that statement is false**.

$\displaystyle \overline{({z-\overline{z}})^2~}=\overline{z~}^2 -2\overline{z}z+z^2 $.

Note that $\displaystyle \overline{\overline{z}}=z $ and $\displaystyle \overline{z^2}=\overline{z}^2 $ - Jan 20th 2010, 09:37 AMCaptainBlack
- Jan 20th 2010, 12:15 PMchemekydie
@Plato - x-bar is not a conjugate

@CaptainBlack -

In your process, what happens to the x double bar? How does that get factored out? - Jan 20th 2010, 12:33 PMPlato
- Jan 20th 2010, 01:14 PMCaptainBlack
- Jan 20th 2010, 01:16 PMCaptainBlack
- Jan 20th 2010, 01:38 PMchemekydie
x-bar is the mean.

I was under the assumption that x double bar is the average of the means. I'm not aware that x double bar can be transformed back to regular x bar.

Am I missing something? - Jan 20th 2010, 01:44 PMCaptainBlack
- Jan 21st 2010, 06:02 AMchemekydie
- Jan 21st 2010, 07:16 AMPlato