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