Answer:
The magnitude of a vector is its length.
To calculate the magnitude of a vector in any number of dimensions, square root the sum of the squares of each dimension.
Therefore, if [tex]\vec v=(x,y)[/tex] then its magnitude is:
[tex]|v|=\sqrt{x^2+y^2}[/tex]
Similarly, if [tex]\vec v=(x,y,z)[/tex] then its magnitude is:
[tex]|v|=\sqrt{x^2+y^2+z^2}[/tex]