Question

Complex numbers question;

ω=cos(2π/7)+i sin(2π/7).


α=ω+ω^2+ω^4


Find value of
2α=

Answer 1

\[e^{ix}=cos(x)+isin(x)\]
i'd suggest re-writing it as:
\[ω=e^{i2π/7}\]

Answer 2

i did so just as you have stated and then tried to solve it but what i need is how to simplify solving alpha

Answer 3

wow, wolfram says it is equivalent to:
\[-1 + i\sqrt7\]

Answer 4

yes it is the correct answer but we donot get to use calcs anything else while solving

Answer 5

i'll ask a big gun to check this out. i haven't seen this

@Zarkon please shed light if you can

Answer 6

2 more because I really want to know.

come see this please @UsukiDoll and @dan815