I've done a few. Some may be wrong.
1a. w is a cube root of unity, making w^3 =1. Clearly w=1 is a solution. The roots are equally spaced around the unit circle. Making w=1, cis2pi/3, cis-2pi/3= cos2pi/3 - sin2pi/3.
1b. w^2, w and 1 are cube roots of unity...