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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_fractional_coords(self, cart_coords: Vector3Like) -> np.ndarray: """ Returns the fractional coordinates given cartesian coordinates. Args: cart_coords (3x1 array):
 Cartesian coords. Returns: Fractional coordinates. """

        return dot(cart_coords, self.inv_matrix)