From 3c31741db7dcb8e4a70b1bb604d0226944b04e21 Mon Sep 17 00:00:00 2001
From: Jannis Portmann <jannis@thisfro.ch>
Date: Thu, 24 Jun 2021 18:10:26 +0200
Subject: [PATCH] Add more operators

---
 Mathematik-V-ZF.tex | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Mathematik-V-ZF.tex b/Mathematik-V-ZF.tex
index bfb0a23..9b9091b 100644
--- a/Mathematik-V-ZF.tex
+++ b/Mathematik-V-ZF.tex
@@ -170,7 +170,9 @@ An der stelle $a$ einer Funtkion $f(x)$
 $$f(a) + \frac{f'(a)}{1!}(x-a) + \frac{f''(a)}{2!}(x-a)^2 + \frac{f'''(a)}{3!}(x-a)^3 + ...$$
 
 \section{Operators}
-$$\mathrm{rot} \ u = \nabla \times \vec{u}$$
+$$\mathrm{div} \, \vec{u} = \frac{\partial u}{\partial x} + \frac{\partial v}{\partial y}$$
+
+$$\mathrm{rot} \, \vec{u} = \nabla \times \vec{u} = -\frac{\partial u}{\partial y} + \frac{\partial v}{\partial x}$$
 
 $$\nabla = \begin{pmatrix}
     \frac{\partial}{\partial x},