Solución
N
(
t
)
=
⟨
−
s
e
n
t
,
0
,
c
o
s
t
⟩
\bold{N}(t) = \lang -sent, 0, cost\rang
N
(
t
)
=
⟨
−
se
n
t
,
0
,
cos
t
⟩