import math


def solar_radius_vector_aus(eccentricity_earth_orbit, solar_true_anomaly):
    """Returns the Solar Radius Vector.
    Measured as distance in Astronomical Units, (AUs). 
    With Eccentricity of Earth's Orbit, eccentricity_earth_orbit, and Solar 
    True Anomaly, solar_true_anomaly.
    """
    solar_rad_vector_aus = (1.000001018 * (1 - eccentricity_earth_orbit ** 2)) / (
        1 + eccentricity_earth_orbit * math.cos(math.radians(solar_true_anomaly))
    )
    return solar_rad_vector_aus