'Returns angular velocity of the wave.
Examples
>>> from sympy import symbols
>>> from sympy.physics.optics import TWave
>>> A, phi, f = symbols(\'A, phi, f\')
>>> w = TWave(A, f, phi)
>>> w.angular_velocity
2*pi*f'

@property
def angular_velocity(self):

    return ((2 * pi) * self._frequency)
