Solution to De Moivre's Theorem w/ q=E(Φ)

[aporter1]

Homework Statement

Find what the following formula yields if we substitute q= E(Φ)

the formula is:1+2q+3q^2+...+nq^n-1=(1-(n+1)q^n+nq^n+1)/(1-q^2)

Homework Equations

The Attempt at a Solution

i substituted Φ in for q:

1+2E( Φ)+3E( Φ)^2+...+nE( Φ)^n-1= (1-(n+1)E( Φ)^n +nE( Φ)^n+1)/(1-E( Φ)^2)

now I'm not sure where to go next

 

[micromass]

What is E(Φ) supposed to be??

 

[aporter1]

e of phi