Respuesta :

The unit vector is given by:
 u = v / lvl
 The module of v is:
 lvl = root ((4) ^ 2 + (-8) ^ 2)
 lvl = root (16 + 64)
 lvl = root (80)
 lvl = 4 * root (5)
 Substituting:
 u = 4i-8j / (4 * root (5))
 Rewriting:
 u = i-2j / root (5)
 u = root (5) / 5 i - 2 * root (5) / 5 j
 Answer:
 
The unit vector in the direction of v is:
 
d. sqrt5 / 5 i - 2 sqrt5 / 5 j