Expand knowledge base, add /sources/

1 files changed, 2 insertions, 2 deletions

diff --git a/content/know/concept/euler-equations/index.pdc b/content/know/concept/euler-equations/index.pdc
index 37d2fea..cedfd93 100644
--- a/content/know/concept/euler-equations/index.pdc
+++ b/content/know/concept/euler-equations/index.pdc
@@ -149,7 +149,7 @@ to which we apply a vector identity:
 $$\begin{aligned}
     0
     = \dv{\rho}{t} + \nabla \cdot (\rho \va{v})
-    = \dv{\rho}{t} + \va{v} \cdot \nabla \rho + \rho (\nabla \cdot \va{v})
+    = \dv{\rho}{t} + (\va{v} \cdot \nabla) \rho + \rho (\nabla \cdot \va{v})
 \end{aligned}$$
 
 Thanks to incompressibility, the last term disappears,
@@ -159,7 +159,7 @@ $$\begin{aligned}
     \boxed{
         0
         = \frac{\mathrm{D} \rho}{\mathrm{D} t}
-        = \dv{\rho}{t} + \va{v} \cdot \nabla \rho
+        = \dv{\rho}{t} + (\va{v} \cdot \nabla) \rho
     }
 \end{aligned}$$