1. ## Complex -calcul

Prove that :

$\frac{1}{{\sqrt {3 + 4i} }} + \frac{1}{{\sqrt {3 - 4i} }} = \pm \frac{4}{5}
$

2. Originally Posted by dhiab
Prove that :

$\frac{1}{{\sqrt {3 + 4i} }} + \frac{1}{{\sqrt {3 - 4i} }} = \pm \frac{4}{5}
$
Start by expessing 3 + 4i and 3 - 4i in polar form and then use deMoivres Theorem.

3. Hello dhiab,
I agree with mr. fantastic, but here it is another way.
I hope you will understand!
Bye!

4. Hello, Lucio!

Lovely solution!