Help with De Moivre formula to establish identity

Hello, I am new to the forum here and am not sure if I am posting this in the correct section. I didnt see any section for complex variables and this seemed the closest to complex analysis

I need help establishing the following identity

= + /

That is divided by . (I didnt know how to write that out in tex)

I need help establishing the above identity using DDe Moivre's formula and

Re: Help with De Moivre formula to establish identity

Quote:

Originally Posted by

**flametag2** I need help establishing the following identity

=

+

/

That is

divided by

.

**What in the world does mean?**

Re: Help with De Moivre formula to establish identity

Sorry

that should be

Re: Help with De Moivre formula to establish identity

This is a bit cumbersome to do with De Moivre's formula.

Are you allowed to use Euler's formula instead?

That is:

or rather:

Re: Help with De Moivre formula to establish identity

No, unfortunately not. We have to use De Moivre's formula :(

Re: Help with De Moivre formula to establish identity

Ah well, basically it's the same thing:

Add:

To find:

or:

If we define , we get:

Perhaps you can substitute that...

Re: Help with De Moivre formula to establish identity