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 Re: cross product in complex multiplication (response to post by dskloet) | Reply Sorry, I just copied it and that's it, without the overline..I don't know why :(
 Re: cross product in complex multiplication (response to post by saintila) | Reply Oh, ok. I just went by the quoted text. I see an overline in your post but not in the original post.
 Re: cross product in complex multiplication (response to post by dskloet) | Reply Maybe your browser is not showing the overline style. (Or maybe you just didn't notice it.) But anyway we're using the conjugate of z, so I believe this (just like the article says) is correct:zw = (a - bi) * (c + di) = ac + adi - bci - bdii = (ac + bd) + (ad - bc)i
 Re: cross product in complex multiplication (response to post by flair) | Reply The cross procuct actually is something in three dimensions. The cross product of (x1, y1, z1) and (x2, y2, z2) is(y1 * z2 - y2 * z1, z1 * y2 - z2 * y1, x1 * y2 - x2 * y1).Now if we see our two vectors as three dimensional vectors with z = 0, the cross product will have x = 0 and y = 0 and z = x1 * y2 - x2 * y1.But looking at the part you quoted, shouldn't that bezw = (a + bi) * (c + di) = ac + adi + bci + bdii = (ac - bd) + (ad + bc)i?So that the real part is the cross product and the imaginary part is the dot product, instead of the other way around?
 cross product in complex multiplication | Reply Sorry for my ignorance.Can some one explain why the complex part is the cross product? Thx.z = a + biw = c + dizw = (ac + bd) + (ad − bc)i Behold! The real part is the dot product, and the complex part is the cross product.
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