diff --git a/scene/graph_scene.py b/scene/graph_scene.py
index a224ba59..d1a3d5e0 100644
--- a/scene/graph_scene.py
+++ b/scene/graph_scene.py
@@ -57,6 +57,11 @@ class GraphScene(Scene):
     def setup(self):
         self.default_graph_colors_cycle = it.cycle(self.default_graph_colors)
 
+        self.left_T_label = VGroup()
+        self.left_v_line = VGroup()
+        self.right_T_label = VGroup()
+        self.right_v_line = VGroup()
+
     def setup_axes(self, animate=False):
         # TODO, once eoc is done, refactor this to be less redundant.
         x_num_range = float(self.x_max - self.x_min)
@@ -291,7 +296,7 @@ class GraphScene(Scene):
 
 
     def get_area(self, graph, t_min, t_max):
-        numerator = max(t_max - t_min, 0.01)
+        numerator = max(t_max - t_min, 0.0001)
         dx = float(numerator) / self.num_rects
         return self.get_riemann_rectangles(
             graph,
@@ -439,13 +444,17 @@ class GraphScene(Scene):
         return group
 
 
-    def add_T_label(self, x_val, color = WHITE, animated = False, **kwargs):
+    def add_T_label(self, x_val, side = RIGHT, label = None, color = WHITE, animated = False, **kwargs):
         triangle = RegularPolygon(n=3, start_angle = np.pi/2)
         triangle.scale_to_fit_height(MED_SMALL_BUFF)
         triangle.move_to(self.coords_to_point(x_val, 0), UP)
         triangle.set_fill(color, 1)
         triangle.set_stroke(width = 0)
-        T_label = TexMobject(self.variable_point_label, fill_color = color)
+        if label == None:
+            T_label = TexMobject(self.variable_point_label, fill_color = color)
+        else:
+            T_label = TexMobject(label, fill_color = color)
+        
         T_label.next_to(triangle, DOWN)
         v_line = self.get_vertical_line_to_graph(
             x_val, self.v_graph,
@@ -462,8 +471,13 @@ class GraphScene(Scene):
         else:
             self.add(triangle, v_line, T_label)
 
-        self.T_label_group = VGroup(T_label, triangle)
-        self.right_v_line = v_line
+        if np.all(side == LEFT):
+            self.left_T_label_group = VGroup(T_label, triangle)
+            self.left_v_line = v_line
+        elif np.all(side == RIGHT):
+            self.right_T_label_group = VGroup(T_label, triangle)
+            self.right_v_line = v_line
+
 
 
 
@@ -472,6 +486,7 @@ class GraphScene(Scene):
         graph,
         new_t_min,
         new_t_max,
+        fade_close_to_origin = True,
         run_time = 1.0
     ):
         curr_t_min = self.x_axis.point_to_number(self.area.get_left())
@@ -482,33 +497,39 @@ class GraphScene(Scene):
             new_t_max = curr_t_max
 
         group = VGroup(self.area)
-        if hasattr(self, "right_v_line"):
-            group.add(self.right_v_line)
-        else:
-            group.add(VGroup())
-        # because update_group expects 3 elements in group
-        if hasattr(self, "T_label_group"):
-            group.add(self.T_label_group)
-        else:
-            group.add(VGroup())
+        group.add(self.left_v_line)
+        group.add(self.left_T_label_group)
+        group.add(self.right_v_line)
+        group.add(self.right_T_label_group)
 
         def update_group(group, alpha):
-            area, v_line, T_label = group
+            area, left_v_line, left_T_label, right_v_line, right_T_label = group
             t_min = interpolate(curr_t_min, new_t_min, alpha)
             t_max = interpolate(curr_t_max, new_t_max, alpha)
             new_area = self.get_area(graph,t_min, t_max)
-            new_v_line = self.get_vertical_line_to_graph(
+            
+            new_left_v_line = self.get_vertical_line_to_graph(
+                t_min, graph
+            )
+            new_left_v_line.set_color(left_v_line.get_color())
+            left_T_label.move_to(new_left_v_line.get_bottom(), UP)
+
+            new_right_v_line = self.get_vertical_line_to_graph(
                 t_max, graph
             )
-            new_v_line.set_color(v_line.get_color())
-            T_label.move_to(new_v_line.get_bottom(), UP)
+            new_right_v_line.set_color(right_v_line.get_color())
+            right_T_label.move_to(new_right_v_line.get_bottom(), UP)
 
-            #Fade close to 0
-            if len(T_label) > 0:
-                T_label[0].set_fill(opacity = min(1, t_max)) 
+            # Fade close to 0
+            if fade_close_to_origin:
+                if len(left_T_label) > 0:
+                    left_T_label[0].set_fill(opacity = min(1, np.abs(t_min))) 
+                if len(right_T_label) > 0:
+                    right_T_label[0].set_fill(opacity = min(1, np.abs(t_max))) 
 
             Transform(area, new_area).update(1)
-            Transform(v_line, new_v_line).update(1)
+            Transform(left_v_line, new_left_v_line).update(1)
+            Transform(right_v_line, new_right_v_line).update(1)
             return group
 
         return UpdateFromAlphaFunc(group, update_group, run_time = run_time)