Vector question. Please help!!!?

Question

 Given that a=5i-12j and that b=pi+j, find:
(i) the unit vector in the direction of a.

Please show steps and thanks in advance. :-)

Update : I checked the answer and it is 1/13(5i-12j). Why?

 

 

Answer 1

Calculate the unit vector

u= a/|a|

  =5i-12j/sqrt((5)^2+(-12)^2)

   =5i-12j/13