Litipk\BigNumbers\Decimal::arccos PHP Méthode

    public function arccos($scale = null)
    {
        if ($this->comp(DecimalConstants::one(), $scale + 2) === 1 || $this->comp(DecimalConstants::negativeOne(), $scale + 2) === -1) {
            throw new \DomainException("The arccos of this number is undefined.");
        }
        $piOverTwo = DecimalConstants::pi()->div(Decimal::fromInteger(2), $scale + 2)->round($scale);
        if ($this->round($scale)->isZero()) {
            return $piOverTwo;
        }
        if ($this->round($scale)->equals(DecimalConstants::one())) {
            return DecimalConstants::zero();
        }
        if ($this->round($scale)->equals(DecimalConstants::negativeOne())) {
            return DecimalConstants::pi()->round($scale);
        }
        $scale = $scale === null ? 32 : $scale;
        return $piOverTwo->sub(self::powerSerie($this, DecimalConstants::zero(), $scale))->round($scale);
    }