Quaternion: Difference between revisions

170 bytes added ,  15 October 2020
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The conjugate is <math>\bar{q} = (q_0, -\mathbf{q})</math>.
The conjugate is <math>\bar{q} = (q_0, -\mathbf{q})</math>.
===Multiplication===
===Multiplication===
Multiplication is <math>q * p = (q_0 p_0 - \mathbf{q} \cdot \mathbf{p}, q_0 \mathbf{p} + p_0 \mathbf{q} + \mathbf{q} \times \mathbf{p})</math>.
Multiplication is <math>q * p = (q_0 p_0 - \mathbf{q} \cdot \mathbf{p}, q_0 \mathbf{p} + p_0 \mathbf{q} + \mathbf{q} \times \mathbf{p})</math>. 
 
Similar to imaginary numbers, <math>i*i=j*j=k*k=-1</math>. 
Multiplication between bases follow cross product rules: <math>i * j = k</math>, <math>j * i = -k</math>.


Intuition: Left multiplication by a quaternion is a 4D rotation plus a scaling operation.
Intuition: Left multiplication by a quaternion is a 4D rotation plus a scaling operation.