Minor fixes for slides of session 3

Author: lumbric

session3_scientific_ecosystem/slides_session3.ipynb

@@ -27,7 +27,7 @@
    "source": [
     "# The Python Scientific Ecosystem\n",
     "\n",
-    "<br><br><br><br><br><br><br><br><br><br><br><br><br><br>\n",
+    "<br><br><br><br><br><br><br><br><br><br><br>\n",
     "<div style=\"font-size:0.8em; color: #555\">2019-04-04 Session 3\n",
     "<span style=\"float:right\">Peter Regner</span>\n",
     "</div>"
@@ -3120,9 +3120,9 @@
     }
    },
    "source": [
-    "# Exercise: plot cos(x) * cos(y)\n",
+    "# Exercise: plot cos(x) * sin(y)\n",
     "\n",
-    "Plot  $f(x,y) := cos(x) * cos(y)$!\n",
+    "Plot  $f(x,y) := cos(x) * sin(y)$!\n",
     "\n",
     "(for $x,y \\in \\mathbb{R}, -10 \\leq x \\leq 10, -10 \\leq y \\leq 10$ with a resolution of $300 \\times 300$)\n",
     "\n",