Hey, I've been stuck on this question for a while so was hoping if someone could help me with parts c and d. (parts a and b given for context)
a) obtain cos6θ as a polynomial in cosθ.
b) Hence show that x=cos ((2k+1) π)/12 where k=0,1,2,3,4,5 are the roots of the equation 32x^6-48x^4+18x^2-1=0...