Respuesta :

Dot product is 
a*b = |a|*|b|*cosα.
In our case
u*u =|u|*|u|*cos 0
u*u =|u|*|u|
12=|u|²
|u|=√12=√(4*3)=2√3
Answer: D. 2√3
NerdyPerson

Answer:

D. 2√3

Step-by-step explanation:

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