Vectors are equivalent if they have the same magnitude and direction. Which are equivalent vectors?

In the diagram ABCDEF is a regular hexagon with centre O.  $$\overrightarrow{OA}=a\ and\ \overrightarrow{AB}\ =b$$

Find expressions, in terms of  a and b, for: $$\overrightarrow{CA}$$  

Find the position vector of AB with initial point A(0, 8) and terminal point B(-9, -3)

If y = 2i and z = -i - 4j, find 3y - 2z.

Find the magnitude of AB if the vector A = 5i + 3j and B = 3i + 9j.

Given u = 4i + 10j -5k and v = -3i + 7j -12k. Calculate u x v

The cross product of the vectors 3i + 4j - 5k and -i + j - 2k is _______________.

 If $$v=2i+4j$$  and  $$w=3i-2j$$  what is the $$magnitude\ of\ v-w?$$  

 If $$v=2i+4j$$  and  $$w=3i-2j$$  what is  $$2v+w?$$  

Find the angle between vectors (1,3) and (2,-5).

If $$\overrightarrow{\ \ a}=3i\ +5j+k\ \ and\ \overrightarrow{\ \ b}=2i+j+3k\ then\ \overrightarrow{\ \ a}\ .\overrightarrow{\ \ b}=$$  

Given $$a=2i+3j+4k$$  
              $$b=-i-2j-3k$$  
Find  $$\theta$$  

Given that  $$M=\left(1,2\right)$$  and  $$N=\left(3,6\right)$$  , find   $$\left|\overrightarrow{MN}\right|$$  .

Given that  $$A=\left(3,1\right)$$  and  $$B=\left(7,4\right)$$  , find unit vector of  $$\overrightarrow{AB}$$  .

A resultant vector is