Solución
u
=
⟨
−
4
5
s
e
n
t
,
−
4
5
c
o
s
t
,
−
2
5
⟩
\bold{u} = \bigg \lang −\frac{4}{\sqrt{5}}sent, −\frac{4}{\sqrt{5}}cost, −\frac{2}{\sqrt{5}}\bigg \rang
u
=
⟨
−
5
4
se
n
t
,
−
5
4
cos
t
,
−
5
2
⟩