UPdate nitsche due to typo (#38)

chapter1/nitsche.ipynb

@@ -75,7 +75,7 @@
     "We create bilinear and linear form, $a$ and $L$\n",
     "\\begin{align}\n",
     "    a(u, v) &= \\int_{\\Omega} \\nabla u \\cdot \\nabla v~\\mathrm{d}x + \\int_{\\partial\\Omega}-(n \\cdot\\nabla u) v - (n \\cdot \\nabla v) u + \\frac{\\alpha}{h} uv~\\mathrm{d}s,\\\\\n",
-    "    L(v) &= \\int_{\\Omega} fv~\\mathrm{d}x + \\int_{\\partial\\Omega} -(n \\cdot \\nabla) u_D + \\frac{\\alpha}{h} u_Dv~\\mathrm{d}s\n",
+    "    L(v) &= \\int_{\\Omega} fv~\\mathrm{d}x + \\int_{\\partial\\Omega} -(n \\cdot \\nabla v) u_D + \\frac{\\alpha}{h} u_Dv~\\mathrm{d}s\n",
     "\\end{align}"
    ]
   },