import math


def spherical_to_cartesian(r, theta, phi):
    """
    :param r: Radius.
    :param theta: in radians.
    :param phi: azimuth angle in radians
    :return: x=[x1, x2, x3] coordinates.
    """
    return [r*math.sin(phi)*math.cos(theta), r*math.sin(phi)*math.sin(theta), r*math.cos(phi)]