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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_f1rx(self, C, r_x, r_1):
 """ Defines the f1 scaling coefficient defined in equation 9 """

        rxr1 = r_x / r_1
        return C["h1"] + (C["h2"] * rxr1) + (C["h3"] * (rxr1 ** 2.))