bc6137…: “According to a polite octahedron”

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Select all of the following statements that must be true:

Given any nonzero vector $\vec {u}$ , the vector $\frac {\vec {u}}{|\vec {u}|}$ has magnitude $1$ . Given any nonzero vectors $\vec {u}$ and $\vec {v}$ with the same dimension, $|\vec {u}+\vec {v}| = |\vec {u}| + |\vec {v}|$ . If $\vec {u} = 3\vec {v}$ , then $|\vec {u}+\vec {v}| = |\vec {u}| + |\vec {v}|$ If $|\vec {u}| = 5$ , then $|6\vec {u}| = 30$ . If $\vec {u} = \vector {u_1,u_2,u_3}$ and $\vec {v} = \vector {v_1,v_2,v_3}$ , then $\vec {u} = \vec {v}$ if and only if: $u_1=v_1 \qquad u_2=v_2 \qquad u_3=v_3 \qquad$ If $|\vec {u}| = |\vec {v}|$ , then $\vec {u} = \vec {v}$ . If $\vec {u} = \vec {v}$ , then $|\vec {u}| = |\vec {v}|$ .