MathPHP\Probability\Distribution\Continuous\F::PDF PHP Метод

    public static function PDF($x, int $d₁, int $d₂)
    {
        Support::checkLimits(self::LIMITS, ['x' => $x, 'd₁' => $d₁, 'd₂' => $d₂]);
        // Numerator
        $⟮d₁x⟯ᵈ¹d₂ᵈ² = ($d₁ * $x) ** $d₁ * $d₂ ** $d₂;
        $⟮d₁x＋d₂⟯ᵈ¹⁺ᵈ² = ($d₁ * $x + $d₂) ** ($d₁ + $d₂);
        $√⟮d₁x⟯ᵈ¹d₂ᵈ²／⟮d₁x＋d₂⟯ᵈ¹⁺ᵈ² = sqrt($⟮d₁x⟯ᵈ¹d₂ᵈ² / $⟮d₁x＋d₂⟯ᵈ¹⁺ᵈ²);
        // Denominator
        $xB⟮d₁／2、d₂／2⟯ = $x * Special::beta($d₁ / 2, $d₂ / 2);
        return $√⟮d₁x⟯ᵈ¹d₂ᵈ²／⟮d₁x＋d₂⟯ᵈ¹⁺ᵈ² / $xB⟮d₁／2、d₂／2⟯;
    }