1 files changed, 32 insertions, 0 deletions
diff --git a/FSF-2020/approximations-and-optimizations/Critical-Points/file 4_f(x,y) = (y-x)(1-2x-3y).py b/FSF-2020/approximations-and-optimizations/Critical-Points/file 4_f(x,y) = (y-x)(1-2x-3y).py
new file mode 100644
index 0000000..72c93b1
--- /dev/null
+++ b/FSF-2020/approximations-and-optimizations/Critical-Points/file 4_f(x,y) = (y-x)(1-2x-3y).py
@@ -0,0 +1,32 @@
+from manimlib.imports import*
+
+class ExampleAnimation(ThreeDScene):
+    def construct(self):
+        axes = ThreeDAxes()
+
+        f_text = TextMobject("$f(x,y) = (y-x)(1-2x-3y)$").to_corner(UL)        
+        d = Dot(np.array([0,0,0]), color = '#800000')   #---- Critical Point
+        d_text = TextMobject("$(0.2,0.2)$",color = '#DC143C').scale(0.5).shift(0.2*UP)  #----x = 0.2, y = 0.2
+        r_text=TextMobject("Critical Point",color = '#00FFFF').shift(0.3*DOWN).scale(0.6)
+
+        #----f(x,y) = (y-x)(1-2x-3y)
+        f = ParametricSurface(
+            lambda u, v: np.array([
+                u,
+                v,
+                (v-u)*(1-2*u-3*v)
+            ]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [PURPLE_D, PURPLE_E],
+            resolution=(20, 20)).scale(1)       
+        
+        self.set_camera_orientation(phi = 75 * DEGREES)
+        self.begin_ambient_camera_rotation(rate=0.5)
+
+        self.add_fixed_in_frame_mobjects(f_text)
+        self.wait(1) 
+        self.add(axes)
+        self.play(Write(f),Write(d))
+        self.wait(1)
+        self.add_fixed_in_frame_mobjects(d_text)
+        self.wait(1)
+        self.add_fixed_in_frame_mobjects(r_text)
+        self.wait(3)