If a and b are the roots of the equation x^2 - x + 1 = 0

If a and b are the roots of the equation x2 - x + 1 = 0, then a2009 + b2009 is equal to

  1. -2
  2. 2
  3. -1
  4. 1

Answer

x2 - x + 1 = 0

x = 1/2 + √3/2i , 1/2 - √3/2i

a = eiπ/3 , b = e-iπ/3

Putting values of a and b:

= 2cos(669 + 2/3)π

The correct option is D.