Difference between revisions of "Addition of quaternions"

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{{Navigation|before=[[Pure and unit quaternions]]|overview=[[Quaternions]]|next=[[Multiplication of quaternions]]}}
 
{{Navigation|before=[[Pure and unit quaternions]]|overview=[[Quaternions]]|next=[[Multiplication of quaternions]]}}
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Two quaternions can easily be added by adding their components.
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Assume two quaternions:
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:<math>
 +
\begin{align}
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q &= q_0 + q_1i + q_2j + q_3k \\
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p &= p_0 + p_1i + p_2j + p_3k
 +
\end{align}
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</math>
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The quaternions <math>q</math> and <math>p</math> can just be replaced by these equations in their addition <math>q+p</math> and then be summarized as the individual four components:
 +
:<math>
 +
\begin{align}
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q+p &= q_0 + q_1i + q_2j + q_3k + p_0 + p_1i + p_2j + p_3k \\
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&= (q_0+p_0) + (q_1+p_1)i + (q_2+p_2)j + (q_3+p_3)k
 +
\end{align}
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</math>
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So the addition in vector notation can be written as:
 +
:<math>
 +
\begin{align}
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q+p &= q_0+p_0 \oplus \vec{\mathbf{q}}+\vec{\mathbf{p}}
 +
\end{align}
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</math>
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Obviously addition of two quaternions is ''commutative'' and ''associative'':
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:<math>
 +
\begin{align}
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q+p&=p+q \\
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(q+p)+r&=q+(p+r)
 +
\end{align}
 +
</math>
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[[Category:Article]]
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[[Category:Quaternion]]

Latest revision as of 16:24, 4 September 2015

← Back: Pure and unit quaternions Overview: Quaternions Next: Multiplication of quaternions

Two quaternions can easily be added by adding their components.

Assume two quaternions:


\begin{align}
q &= q_0 + q_1i + q_2j + q_3k \\
p &= p_0 + p_1i + p_2j + p_3k
\end{align}

The quaternions q and p can just be replaced by these equations in their addition q+p and then be summarized as the individual four components:


\begin{align}
q+p &= q_0 + q_1i + q_2j + q_3k + p_0 + p_1i + p_2j + p_3k \\
&= (q_0+p_0) + (q_1+p_1)i + (q_2+p_2)j + (q_3+p_3)k
\end{align}

So the addition in vector notation can be written as:


\begin{align}
q+p &= q_0+p_0 \oplus \vec{\mathbf{q}}+\vec{\mathbf{p}}
\end{align}

Obviously addition of two quaternions is commutative and associative:


\begin{align}
q+p&=p+q \\
(q+p)+r&=q+(p+r)
\end{align}