i^2=j^2=k^2=ijk=-1 ij=k, jk=i, ki=j
Q = (cos(θ/2); α sin(θ/2), β sin(θ/2), γ sin(θ/2)) R = (cos(θ/2); -α sin(θ/2), -β sin(θ/2), -γ sin(θ/2)) R P Q = (0; 答え)