# Thread: true or not ??

1. ## true or not ??

show that :
1) $\displaystyle \overline {e^ { i\theta}} = {e^ {-i\theta}}$
proof:

$\displaystyle \overline {e^ {i\theta}} = cos\theta - isin\theta = cos(-\theta) + isin (-\theta ) = {e^ {-i\theta}}$
2)$\displaystyle \mid {e^ { i\theta}}\mid =1$
proof:
$\displaystyle \mid {e^ { i\theta}}\mid =\sqrt{{cos^2}\theta +{sin^2}\theta} = \sqrt {1}=1$

2. Yes that works.
BTW: If you have more than one character in an exponent, set off the whole exponent in braces.
$$x^{-i\theta}$$ gives $\displaystyle x^{-i\theta}$ instead of $\displaystyle x^-i \theta$.