Best AnswerIt looks like we are trying to find the magnitude of this vector.

We can use Pythagoras' theorem to calculate this:

||**v**|| = √( x^{2} + y^{2} )

||**v**|| = √( (4)^{2} + (3)^{2} )

||**v**|| = √( 16 + 9 )

||**v**|| = √25

||**v**|| = 5

Source: http://www.mathsisfun.com/algebra/vectors.html