Answer:
[tex]\[\sqrt{5}\][/tex]
Step-by-step explanation:
The given vector is represented by (2,-1).
This can be represented in general form as (x,y) where x=2 and y=-1.
Magnitude of the vector represented as (x,y) is given by [tex][\sqrt{x^{2}+y^{2}}\][/tex]
Evaluating for the given values of x and y,
[tex]\[\sqrt{2^{2}+(-1)^{2}}\][/tex][tex]\[=\sqrt{4+1}\][/tex]
[tex]\[=\sqrt{5}\][/tex]
Length of the vector is [tex]\[\sqrt{5}\][/tex]
