fix typos

Author: jkbren

notebooks/class_02/class_02_networkx1.ipynb

@@ -92,6 +92,7 @@
     "\\end{pmatrix},$$\n",
     " \n",
     "where $\\forall i,j \\in V$, \n",
+    "\n",
     "$$a_{ij} =\n",
     "\\begin{cases}\n",
     "    1    & \\quad \\text{if } e_{ij} \\in E\\\\\n",
@@ -119,6 +120,7 @@
     "$$\n",
     " \n",
     "where $\\forall i,j \\in V$,\n",
+    "\n",
     "$$w_{ij} =\n",
     "\\begin{cases}\n",
     "    w    & \\quad \\text{if } e_{ij} \\in E\\\\\n",
@@ -313,7 +315,9 @@
     "    \\vdots  & \\vdots  & \\ddots & \\vdots  \\\\\n",
     "    b_{N_1,1} & b_{N,2} & \\cdots & b_{N_1,N_2} \n",
     "\\end{pmatrix},$$\n",
+    "\n",
     "where $N_1 = |V_1|$, $N_2 = |V_2|$, and $\\forall i \\in V_1$ and $j \\in V_2$, \n",
+    "\n",
     "$$b_{i,j} =\n",
     "\\begin{cases}\n",
     "    1    & \\quad \\text{if } e_{i,j} \\in E\\\\\n",
@@ -2241,6 +2245,7 @@
     "$$\n",
     "\n",
     "where $N_1 = |V_1|$, $N_2 = |V_2|$, and $\\forall i \\in V_1$ and $j \\in V_2$, \n",
+    "\n",
     "$$b_{i,j} =\n",
     "  \\begin{cases}\n",
     "    1       & \\quad \\text{if } e_{i,j} \\in E\\\\\n",