Help de moivres theorem question (1 Viewer)

[fartman]

 

[nightweaver066]

Expand using binomial expansion / pascal's triangle (however you do it).

Then simplify the LHS by De Moivre's theorem becoming

Equate the real and imaginary components.

Using , you get the required expression.

 

[fartman]

I GOT IT!!!!!!
Thanks alot!

 

[Carrotsticks]

Haha I don't like these questions.

So much writing.

 

[math man]

you should see how fast i do lol, i take like 20-30 secs max

 

[math man]

i also say let s= sinx and c= cosx at start

 

[Carrotsticks]

you should see how fast i do lol, i take like 20-30 secs max

The question is "Is it legible?" =p

 

[math man]

umm, i can read it, so good enough