diff --git a/lecture_07/lecture_07.ipynb b/lecture_07/lecture_07.ipynb
index 08d29c4..66fa9a8 100644
--- a/lecture_07/lecture_07.ipynb
+++ b/lecture_07/lecture_07.ipynb
@@ -1435,22 +1435,23 @@
   }
  ],
  "metadata": {
+  "anaconda-cloud": {},
   "kernelspec": {
-   "display_name": "Octave",
-   "language": "octave",
-   "name": "octave"
+   "display_name": "Python [conda root]",
+   "language": "python",
+   "name": "conda-root-py"
   },
   "language_info": {
-   "file_extension": ".m",
-   "help_links": [
-    {
-     "text": "MetaKernel Magics",
-     "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
-    }
-   ],
-   "mimetype": "text/x-octave",
-   "name": "octave",
-   "version": "0.19.14"
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.5.2"
   }
  },
  "nbformat": 4,
diff --git a/lecture_07/mod_secant.m b/lecture_07/mod_secant.m
index a3caa10..df97983 100644
--- a/lecture_07/mod_secant.m
+++ b/lecture_07/mod_secant.m
@@ -14,13 +14,13 @@
 %   ea = approximate relative error (%)
 %   iter = number of iterations
 if nargin<3,error('at least 3 input arguments required'),end
-if nargin<4 || isempty(es),es=0.0001;end
+if nargin<4 || isempty(es),es=0.0001;end	
 if nargin<5 || isempty(maxit),maxit=50;end
-iter = 0;
+iter = 0
 while (1)
   xrold = xr;
   dfunc=(func(xr+dx)-func(xr))./dx;
-  xr = xr - func(xr)/dfunc;
+  xr = xr - func(xr)/dfunc; %calculate as an approximation
   iter = iter + 1;
   if xr ~= 0 
     ea = abs((xr - xrold)/xr) * 100;