def fdiff(self, argindex=1):
    '\n        Returns the first derivative of this function.\n        '
    if (argindex == 1):
        return (((sympy.exp(*self.args) * (self.args[0] - S.One)) + S.One) / (self.args[0] ** 2))
    else:
        raise sympy.ArgumentIndexError(self, argindex)
Returns the first derivative of this function.
def fdiff(self, argindex=1):
    '\n        \n        '
    if (argindex == 1):
        return (((sympy.exp(*self.args) * (self.args[0] - S.One)) + S.One) / (self.args[0] ** 2))
    else:
        raise sympy.ArgumentIndexError(self, argindex)