Find the unit tangent vector to the curve defined by r
(t)=⟨5cos(t),5sin(t),2sin 2
(t)⟩ at t= 2
π
​
. T
( 2
π
​
)= Use the unit tangent vector to write the parametric equations of a tangent line to the curve at t= 2
π
​
. x(t)=
y(t)=
z(t)=
​