Answer:

Step-by-step explanation:
The unit vector for a nonzero vector, say u, in the direction of u is given by:
û =
---------------(i)
Where;
|u| = magnitude of vector u
From the question;
u = (4, -4)
First let's calculate the magnitude of u as follows;
|u| = 
|u| = 
|u| =
= 
Now, substitute u and |u| into equation (i) as follows;
û = 
û = 
û = 
Therefore, the unit vector is 
5.3851648071..... is the irrational number your looking for