Where $a=ix$ and $b=-ix$ then what is: $|a+b|^2$
$|b-a|^2$
And then is this equality true?
$|a+b|^2=|a|^2+|b|^2$ because it seems $a+b=0$!
Where $a=ix$ and $b=-ix$ then what is: $|a+b|^2$
$|b-a|^2$
And then is this equality true?
$|a+b|^2=|a|^2+|b|^2$ because it seems $a+b=0$!
You have $a+b=0$ and $b-a=-2ix$ so $|a+b|=0$ and $|b-a|=2|x|$ Since $|a+b|^2=0$ and $|a|^2 + |b|^2 = 2|x|^2$ you have not this équality in general. The general formula about complexe numbers is : $|a+b|^2=|a|^2 + |b|^2 + 2 {\mathcal R}e(\overline ab)$