CSflim

I'm trying to learn the formula for multiplying quaternions, but I don't understand it. I can use it alright, I just don't see any pattern to it. For all I can see it is just an abitrary collection of terms. (unlike addition and subtraction which are obvious)


( w + x i + y j + z k ) *
(w' + x'i + y'j + z'k )

=
(ww' - xx' - yy' - zz')
+(wx' + xw' + yz' - zy')i
+(wy' + yw' + zx' - xz')j
+(wz' + zw' + xy' - yx')k


Does anyone know a pattern or a pnemonic of some kind that would halp me remember this? Because I'm not in the mood for for learning off a 16 term formula! (yes. I'm lazy).

Thanks.

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