1 files changed, 78 insertions, 0 deletions
diff --git a/FSF-2020/calculus/intro-to-calculus/intro-to-derivative/derivative2.py b/FSF-2020/calculus/intro-to-calculus/intro-to-derivative/derivative2.py
new file mode 100644
index 0000000..d6aab15
--- /dev/null
+++ b/FSF-2020/calculus/intro-to-calculus/intro-to-derivative/derivative2.py
@@ -0,0 +1,78 @@
+from manimlib.imports import *
+class derivative2(GraphScene, MovingCameraScene):
+	def setup(self):
+		GraphScene.setup(self)
+		MovingCameraScene.setup(self)
+	CONFIG = {
+		"y_max" : 100,
+        "y_min" : 0,
+        "x_max" : 10,
+        "x_min" : 0,
+        "y_tick_frequency" : 100, 
+        "x_tick_frequency" : 10, 
+        "axes_color" : WHITE, 
+        "num_graph_anchor_points": 3000, #this is the number of points that graph manim
+        "graph_origin" : ORIGIN,
+        "x_labeled_nums": None,#list(range(0,11)),
+        "y_labeled_nums": None,#list(range(0,101))[::10],
+        "x_axis_label":"$x$",
+        "y_axis_label":"$f(x)$",
+        "x_axis_width": 5,
+        "y_axis_height": 5,
+        "start_x" : 2,
+        "start_dx" : 6,
+        "df_color" : YELLOW,
+        "dx_color" : GREEN,
+        "secant_line_color" : MAROON_B,
+        "zoomed_camera_frame_starting_position": ORIGIN+2*DOWN+6*LEFT,
+	}
+	def construct(self):
+		self.setup()
+		self.camera_frame.save_state()
+		self.graph_origin = ORIGIN+2*DOWN+6*LEFT
+		self.setup_axes()
+		graph23 = self.get_graph(lambda x : x**2+7, color = GREEN_SCREEN, x_min = 0, x_max = 10)
+		graph24 = self.get_graph(lambda x : x**2+7, color = GREEN_SCREEN, x_min = 8, x_max = 2.01)
+		line_1 = DashedVMobject(Line(np.array([-5,-2,0]), np.array([-5,-1.42,0])))
+		textdef = TextMobject("")
+		text1 = TexMobject("{ x }_{ 0 }").move_to(np.array([-5,-2.2,0]))
+		text2 = TextMobject("The line becomes tangential to the curve").move_to(self.graph_origin+RIGHT+0.5*UP).scale(0.01)
+		text3 = TexMobject(r"\frac { df }{ dx } =\frac { f({ x }_{ 0 }+h)-f({ x }_{ 0 }) }{ h-0 }").move_to(2*RIGHT)
+		text4 = TexMobject(r"\frac { df }{ dx } =\lim _{ h\rightarrow 0 }{ \frac { f({ x }_{ 0 }+h)-f({ x }_{ 0 }) }{ h }  }").move_to(2*RIGHT)  
+		squareobj = Square(side_length = 15).move_to(self.graph_origin+RIGHT+0.53*UP)
+		ss_group = self.get_secant_slope_group(
+            self.start_x, graph23,
+            dx = self.start_dx,
+            dx_label = "h",
+            df_label = "df",
+            df_line_color = self.df_color,
+            dx_line_color = self.dx_color,
+            secant_line_color = self.secant_line_color,
+            dot_df_top = True,
+            dot_dx_start = True,
+            dot_df_top_label = "Q",
+            dot_dx_start_label = "P",
+            secant_line_length = 8
+        )
+		self.play(ShowCreation(graph23))
+		self.wait()
+		self.play(ShowCreation(ss_group.secant_line))
+		self.add(text1)
+		self.play(ShowCreation(line_1))
+		self.wait(3)
+		self.play(ShowCreation(ss_group.dx_line))
+		self.play(ShowCreation(ss_group.dx_label))
+		self.play(ShowCreation(ss_group.df_line))
+		self.play(Write(ss_group.df_label))
+		self.play(ShowCreation(ss_group.dot_df_top), ShowCreation(ss_group.dot_dx_start))
+		self.play(ShowCreation(ss_group.dot_df_top_label), ShowCreation(ss_group.dot_dx_start_label))
+		self.wait()
+		self.play(ShowCreation(text3))
+		self.wait(2)
+		self.play(ReplacementTransform(text3, text4))
+		self.animate_secant_slope_group_change(ss_group, target_dx = 0.01, run_time = 5)
+		self.wait(2)
+		self.play(self.camera_frame.set_width,0.2,self.camera_frame.move_to,squareobj,run_time = 2)
+		self.wait()
+		self.play(ShowCreation(text2))
+		self.wait(3)