diff --git a/apps/graph/Makefile b/apps/graph/Makefile
index 470b83c1a..c014d5ea7 100644
--- a/apps/graph/Makefile
+++ b/apps/graph/Makefile
@@ -3,8 +3,6 @@ app_headers += apps/graph/app.h
 
 app_objs += $(addprefix apps/graph/,\
   app.o\
-  cartesian_function.o\
-  cartesian_function_store.o\
   storage_cartesian_function_store.o\
   graph/banner_view.o\
   graph/calculation_graph_controller.o\
diff --git a/apps/graph/cartesian_function.h b/apps/graph/cartesian_function.h
deleted file mode 100644
index b9339d68e..000000000
--- a/apps/graph/cartesian_function.h
+++ /dev/null
@@ -1,27 +0,0 @@
-#ifndef GRAPH_CARTESIAN_FUNCTION_H
-#define GRAPH_CARTESIAN_FUNCTION_H
-
-#include "../shared/function.h"
-
-namespace Graph {
-
-class CartesianFunction : public Shared::Function {
-public:
-  using Shared::Function::Function;
-  CartesianFunction(const char * text = nullptr, KDColor color = KDColorBlack);
-  bool displayDerivative();
-  void setDisplayDerivative(bool display);
-  double approximateDerivative(double x, Poincare::Context * context) const;
-  double sumBetweenBounds(double start, double end, Poincare::Context * context) const override;
-  Poincare::Expression::Coordinate2D nextMinimumFrom(double start, double step, double max, Poincare::Context * context) const;
-  Poincare::Expression::Coordinate2D nextMaximumFrom(double start, double step, double max, Poincare::Context * context) const;
-  double nextRootFrom(double start, double step, double max, Poincare::Context * context) const;
-  Poincare::Expression::Coordinate2D nextIntersectionFrom(double start, double step, double max, Poincare::Context * context, const Shared::Function * function) const;
-  const char * symbol() const override { return "x"; }
-private:
-  bool m_displayDerivative;
-};
-
-}
-
-#endif
diff --git a/apps/graph/cartesian_function_store.cpp b/apps/graph/cartesian_function_store.cpp
deleted file mode 100644
index 4b2215624..000000000
--- a/apps/graph/cartesian_function_store.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-#include "cartesian_function_store.h"
-extern "C" {
-#include <assert.h>
-#include <stddef.h>
-}
-#include <ion.h>
-
-namespace Graph {
-
-constexpr int CartesianFunctionStore::k_maxNumberOfFunctions;
-constexpr const char * CartesianFunctionStore::k_functionNames[k_maxNumberOfFunctions];
-
-CartesianFunctionStore::CartesianFunctionStore() :
-  Shared::FunctionStore()
-{
-  addEmptyModel();
-}
-
-uint32_t CartesianFunctionStore::storeChecksum() {
-  size_t dataLengthInBytes = k_maxNumberOfFunctions*sizeof(uint32_t);
-  assert((dataLengthInBytes & 0x3) == 0); // Assert that dataLengthInBytes is a multiple of 4
-  uint32_t checksums[k_maxNumberOfFunctions];
-  for (int i = 0; i < k_maxNumberOfFunctions; i++) {
-    checksums[i] = m_functions[i].checksum();
-  }
-  return Ion::crc32((uint32_t *)checksums, dataLengthInBytes/sizeof(uint32_t));
-}
-
-
-char CartesianFunctionStore::symbol() const {
-  return 'x';
-}
-
-void CartesianFunctionStore::removeAll() {
-  FunctionStore::removeAll();
-  addEmptyModel();
-}
-
-CartesianFunction * CartesianFunctionStore::emptyModel() {
-  static CartesianFunction addedFunction("", KDColorBlack);
-  addedFunction = CartesianFunction(firstAvailableName(), firstAvailableColor());
-  return &addedFunction;
-}
-
-CartesianFunction * CartesianFunctionStore::nullModel() {
-  static CartesianFunction emptyFunction("", KDColorBlack);
-  return &emptyFunction;
-}
-
-void CartesianFunctionStore::setModelAtIndex(Shared::ExpressionModel * e, int i) {
-  assert(i>=0 && i<m_numberOfModels);
-  m_functions[i] = *(static_cast<CartesianFunction *>(e));
-}
-
-}
diff --git a/apps/graph/cartesian_function_store.h b/apps/graph/cartesian_function_store.h
deleted file mode 100644
index f71851f9b..000000000
--- a/apps/graph/cartesian_function_store.h
+++ /dev/null
@@ -1,39 +0,0 @@
-#ifndef GRAPH_CARTESIAN_FUNCTION_STORE_H
-#define GRAPH_CARTESIAN_FUNCTION_STORE_H
-
-#include "cartesian_function.h"
-#include "../shared/function_store.h"
-#include <stdint.h>
-#include <escher.h>
-
-namespace Graph {
-
-class CartesianFunctionStore : public Shared::FunctionStore {
-public:
-  CartesianFunctionStore();
-  uint32_t storeChecksum() override;
-  CartesianFunction * modelAtIndex(int i) override { return &m_functions[i]; }
-  CartesianFunction * activeFunctionAtIndex(int i) override { return (CartesianFunction *)Shared::FunctionStore::activeFunctionAtIndex(i); }
-  CartesianFunction * definedFunctionAtIndex(int i) override { return (CartesianFunction *)Shared::FunctionStore::definedFunctionAtIndex(i); }
-  int maxNumberOfModels() const override {
-    return k_maxNumberOfFunctions;
-  }
-  char symbol() const override;
-  void removeAll() override;
-  static constexpr int k_maxNumberOfFunctions = 4;
-private:
-  static constexpr const char * k_functionNames[k_maxNumberOfFunctions] = {
-    "f", "g", "h", "p",
-  };
-  CartesianFunction * emptyModel() override;
-  CartesianFunction * nullModel() override;
-  void setModelAtIndex(Shared::ExpressionModel * f, int i) override;
-  const char * firstAvailableName() override {
-    return firstAvailableAttribute(k_functionNames, FunctionStore::name);
-  }
-  CartesianFunction m_functions[k_maxNumberOfFunctions];
-};
-
-}
-
-#endif
diff --git a/apps/shared/storage_cartesian_function.cpp b/apps/shared/storage_cartesian_function.cpp
index b227ae20f..b7c4df953 100644
--- a/apps/shared/storage_cartesian_function.cpp
+++ b/apps/shared/storage_cartesian_function.cpp
@@ -1,6 +1,8 @@
 #include "storage_cartesian_function.h"
 #include "storage_expression_model_store.h"
 #include "poincare_helpers.h"
+#include <poincare/derivative.h>
+#include <poincare/integral.h>
 #include <float.h>
 #include <cmath>