8.2 Cook-Toom algorithm 96 Polynomial multiplication s(p)=h(p)x(p) x(p)=x-1p-+●+xp+x0 h(p)=hw-1pN-+●●+hp+h degree s(p)=2+N-2D+N2++Sp+S0 L+N-1 coefficients If s(B),for i=0,1,...,L+N-2 are known,the unique s(p)can be computed as: L+N-2 s(p)=∑s(B,) Πp-B) i=0 Π(B,-B,) 99 8.2 Cook-Toom algorithm s( p)  h( p)x( p) 1 0 1 1 h( p) h p h p h N  N        1 1 1 0 ( ) L L x p x p x p x        2 2 1 0 ( ) L N L N s p s p s p s                     2 0 ( ) ( ) ( ) ( ) L N i j i i j j i j i p s p s      Polynomial multiplication  If s(βi), for i=0,1,…,L+N-2 are known, the unique s(p) can be computed as: degree L+N-1 coefficients