Update app.py

app.py

@@ -44,8 +44,8 @@ def calculate_derivative(func_str):
         # Calculate the derivative
         derivative = sp.diff(func, x)
         # Convert sympy expressions to numerical functions
-        func_lambdified = sp.lambdify(x, func, "numpy")
-        derivative_lambdified = sp.lambdify(x, derivative, "numpy")
+        func_lambdified = sp.lambdify(x_values, func, "numpy")
+        derivative_lambdified = sp.lambdify(x_values, derivative, "numpy")
         return func_lambdified, derivative_lambdified
     except sp.SympifyError:
         st.error("Invalid function input. Please enter a valid mathematical expression.")