Solution
= Solution
The modulus is the <Euclidean norm>, obtained by taking the square root of the <dot product> of the <vector> with itself:
$$
\boxed{\sqrt{1^2+2^2+1^2}=\sqrt6.}
$$
= Solution
The modulus is the <Euclidean norm>, obtained by taking the square root of the <dot product> of the <vector> with itself:
$$
\boxed{\sqrt{1^2+2^2+1^2}=\sqrt6.}
$$