Let $A = \left(1,3\right)$ and $B = \left(-3,4\right)$ be points in $\mathbb{R}^2$, and let $C = \left(0,2,1\right)$ and $D = \left(-3,-1,-1\right)$ be points in $\mathbb{R}^3$.

1. Find the distance between $A$ and $B$.
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2. Find the distance between $C$ and $D$.
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3. Find the distance between the point $(x,y,z)$ and $C$.
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4. Find the length of the vector $\overrightarrow{CD}$.
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5. Find the length of the vector $2 \overrightarrow{BA}$.
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