From 3af8c86504074bae82445fd74c822271b1f2e6a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Tue, 30 May 2017 10:16:36 +0200
Subject: [PATCH] [apps/graph] Fix bug

Change-Id: I13cebe8a1067e09e0b7aac0a613ffe8aab23f60b
---
 apps/graph/cartesian_function.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/apps/graph/cartesian_function.cpp b/apps/graph/cartesian_function.cpp
index 6bee1cecd..b28a05929 100644
--- a/apps/graph/cartesian_function.cpp
+++ b/apps/graph/cartesian_function.cpp
@@ -18,7 +18,7 @@ void CartesianFunction::setDisplayDerivative(bool display) {
 
 float CartesianFunction::approximateDerivative(float x, Poincare::Context * context) const {
   Poincare::Complex abscissa = Poincare::Complex::Float(x);
-  Poincare::Expression * args[2] = {m_expression, &abscissa};
+  Poincare::Expression * args[2] = {expression(), &abscissa};
   Poincare::Derivative derivative;
   derivative.setArgument(args, 2, true);
   return derivative.approximate(*context);