r=x^12 - x^10 + x^8 - x^6 + x^4 - x^2 + 1 q= (x^16 - 2*x^15 + x^14 + x^2 + 2*x + 1)/ 4 P= x^8 - 2*x^7 + 9*x^6 - 14*x^5 + 26*x^4 - 28*x^3 + 25*x^2 - 14*x + 4 v= x-1/x