Return the reciprocal square root of x.

    Return +Inf if x is ±0, +0 if x is +Inf, and NaN if x is negative.

def rec_sqrt(x, context=None):
    """
    Return the reciprocal square root of x.

    Return +Inf if x is ±0, +0 if x is +Inf, and NaN if x is negative.

    """
    return _apply_function_in_current_context(
        BigFloat,
        mpfr.mpfr_rec_sqrt,
        (BigFloat._implicit_convert(x),),
        context,
    )