Update app.py

app.py

@@ -140,8 +140,12 @@ with right_col:
     
     fig = go.Figure()
     fig.add_trace(go.Scatter(x=x_range, y=y_range, mode='lines', name='Equation', line=dict(color='#FFD700')))
+
+    # Get current position from history
     x_current, y_current = st.session_state.history[st.session_state.current_index]
     fig.add_trace(go.Scatter(x=[x_current], y=[y_current], mode='markers', name='Current Position', marker=dict(size=12, color='#FF4500')))
+    
+    # Calculate and plot the updated tangent line at the current position
     tangent_y = calculate_tangent(function_input, x_current, x_range)
     fig.add_trace(go.Scatter(x=x_range, y=tangent_y, mode='lines', name='Tangent', line=dict(dash='dash', color='#00FFFF')))
     
@@ -154,4 +158,5 @@ with right_col:
         width=900,
         margin=dict(l=20, r=20, t=50, b=20),
     )
+    
     st.plotly_chart(fig, use_container_width=True)