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from manimlib.imports import*
class TheoremAnimation(ThreeDScene):
def construct(self):
axes = ThreeDAxes()
#----parabola: x**2+y**2
parabola1 = ParametricSurface(
lambda u, v: np.array([
u,
v,
u**2+v**2
]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [TEAL_E],
resolution = (20, 20)).scale(1)
#----parabola: -x**2-y**2
parabola2 = ParametricSurface(
lambda u, v: np.array([
u,
v,
-u**2-v**2
]),v_min = -1, v_max = 1, u_min = -1, u_max = 1, checkerboard_colors = [PURPLE_E,PURPLE_E],
resolution = (20, 20)).scale(1)
self.set_camera_orientation(phi = 75 * DEGREES)
self.begin_ambient_camera_rotation(rate = 0.4)
d = Dot(np.array([0,0,0]), color = '#800000') #---- critical point
r = Rectangle(fill_color = '#C0C0C0',fill_opacity = 0.3).move_to(ORIGIN) #----tangent plane
parabola1_text = TextMobject("Maximum with horizontal tangent plane").scale(0.7).to_corner(UL)
parabola2_text = TextMobject("Minimum with horizontal tangent plane").scale(0.7).to_corner(UL)
self.add(axes)
self.add_fixed_in_frame_mobjects(parabola2_text)
self.wait(1)
self.play(Write(parabola1))
self.wait(1)
self.play(ShowCreation(d))
self.wait(1)
self.play(ShowCreation(r))
self.wait(2)
self.play(FadeOut(parabola2_text),FadeOut(parabola1),FadeOut(r),FadeOut(d))
self.wait(1)
self.add_fixed_in_frame_mobjects(parabola1_text)
self.wait(1)
self.play(Write(parabola2))
self.wait(1)
self.play(ShowCreation(d))
self.wait(1)
self.play(ShowCreation(r))
self.wait(2)
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