diff --git a/content/GA_1_5/Analysis_solution.ipynb b/content/GA_1_5/Analysis_solution.ipynb
index 29ac086181f1df98e865e4d0d5630b96be18bf2f..61f1980ced3314c50fcc45d0d550abe31d489772 100644
--- a/content/GA_1_5/Analysis_solution.ipynb
+++ b/content/GA_1_5/Analysis_solution.ipynb
@@ -511,7 +511,7 @@
     "$$\n",
     "4f(x_{i-1})-f(x_{i-2})\\approx (4-2)f(x_{i})-(4-2)\\Delta x\\frac{\\partial f(x_{i})}{\\partial x} +(4-4)\\frac{\\Delta x^2}{2}\\frac{\\partial^2 f(x_i)}{\\partial x^2}+\\mathcal{O}(\\Delta x)^3\n",
     "\\newline\\newline\n",
-    "3f(x_i)-4f(x_{i-1})+f(x_{i-2}) \\approx \\frac{\\partial f(x_{i})}{\\partial x} \n",
+    "3f(x_i)-4f(x_{i-1})+f(x_{i-2}) \\approx 2\\Delta x\\frac{\\partial f(x_{i})}{\\partial x} +\\mathcal{O}(\\Delta x)^3\n",
     "\\newline\n",
     "\\frac{3f(x_i)-4f(x_{i-1})+f(x_{i-2})}{2\\Delta x} \\approx \\frac{\\partial f(x_{i})}{\\partial x}+\\mathcal{O}(\\Delta x)^2\n",
     "$$\n",