

Given, x2 - x + 1 = 0
Now, by Shridharacharya formula, we het
x = {1 ± √(1 - 4*1*1) }/2
=> x = {1 ± √(1 - 4) }/2
=> x = {1 ± √(-3)}/2
=> x = {1 ± √(3 * -1)}/2
=> x = {1 ± √3 * √-1}/2
=> x = {1 ± i√3}/2 {since i = √-1}
=> x = {1 + i√3}/2, {--1 - i√3}/2
=> x = -{-1 - i√3}/2, -{-1 + i√3}/2
=> x = w, w2 {since w = {-1 + i√3}/2 and w2 = {-1 - i√3}/2 }
Hence, α = -w, β = w2
Again we know that w3 = 1 and 1 + w + w2 = 0
Now, α2009 + β2009 = α2007 * α2 + β2007 * β2
= (-w)2007 * (-w)2 + (-w2 )2007 * (-w2 )2 {since 2007 is multiple of 3}
= -(w)2007 * (w)2 - (w2 )2007 * (w4 )
= -1 * w2 - 1 * w3 * w
= -1 * w2 - 1 * 1 * w
= -w2 - w
= 1 {since 1 + w + w2 = 0}
So, α2009 + β2009 = 1
