多項式(14)
Author: 藍邦偉　老師

A

$ B $

C

D

E

F

四邊形BCEF的面積為

設\overline{AE}=\overline{AF}=x

16-\frac{1}{2}x²-\frac{1}{2}×4×(4-x)

$ =-\frac{1}{2}x²+2x+8 $

$ =-\frac{1}{2} (x²-4x+4)+10$

$ =-\frac{1}{2}(x-2)²+10≤10 $

故四邊形BCFE的最大面積為10

A = (-8.056375492682927, -2.2701868292682885)
B: A + (5, 0)
D: A + (0, 5)
C: B + D - A
a = Segment(A, B)
b = Segment(B, C)
c = Segment(C, D)
d = Segment(D, A)
E = Point(d)
e = Circle(A, E)
F = Intersect(e, a)
f = Segment(E, F)
h = Segment(C, E)
n = 0 (slider from 0 to 8, step 1)
G = (-5.9267754926829275, 3.936818048780484)
G_1: G + (0.7, 0)
G_3: G + (0, 0.6)
G_2: G_1 + G_3 - G
poly1, g, g_1, g_2, g_3 = Polygon(G, G_1, G_2, G_3)