If and are any two unit vectors

MATHEMATICS · Single correct · A Level · Mathematics · Vectors · Vectors

Problem

\mathbf{a}

and

\mathbf{b}

are any two unit vectors, then the possible integer value of

|\mathbf{a}+\mathbf{b}|+|\mathbf{a}-\mathbf{b}|

is: (1) 2 (2) 3 (3) 4 (4) 5