Find the Unit Tangent Vector $T ( t )$ $$\mathbf { r } ( t ) = \langle 2 \sin t , 4 t , 2 \cos t \}$$

Find the unit tangent vector $T ( t )$ .
$$\mathbf { r } ( t ) = \langle 2 \sin t , 4 t , 2 \cos t \}$$