圖解餘弦定理
Author: 藍邦偉  老師

移動A,B,C觀察

$A$

$B$

$C$

c²

$Step=%v$

b²

b²

a²

a²

absin(C-90°)=-abcosC

c²=a²+b²-2abcosC

圖解餘弦定理

f(x) = 2 * sin(x) + cos(2 * x) + 2
A = (2.92, 3.2600000000000002)
a: y = y(A)
B = Point(a)
b: x = x(A)
c: x = x(B)
d = Circle(A, B)
C = (4.32, 4.32)
D = Intersect(d, b, 2)
E: (x(B), y(D))
e = Segment(A, C)
g = Segment(C, B)
Polygon1, a_1, c_1, h, i, F, G = Polygon(A, C, 4)
Polygon2, c_2, b_1, j, k, H, I = Polygon(C, B, 4)
p = Circle(A, B)
J = Intersect(p, b, 1)
K: (x(B), y(J))
l: x = x(C)
m = Segment(J, K)
n_3 = Segment(D, E)
q = Segment(J, G)
r = Segment(K, H)
P: J + F - G
s = Segment(J, P)
t = Segment(P, F)
d_1 = Segment(P, I)
e_1 = Segment(P, K)
L = Intersect(b, h)
M = Intersect(c, j)
f_1 = Segment(A, B)
g_1 = Segment(B, E)
h_1 = Segment(A, D)
i_1 = Segment(J, A)
j_1 = Segment(K, B)
k_1 = Segment(P, C)
l_1 = Ray(G, F)
N = Intersect(k_1, l_1)
m_1 = Segment(F, N)
n_1 = Ray(H, I)
O = Intersect(k_1, n_1)
p_1 = Segment(O, I)
多邊形1, a_2, b_2, e_2, d_2 = Polygon(A, B, E, D)
多邊形2, l_2, a_3, c_3, n_2 = Polygon(L, A, C, N)
多邊形3, o, c_4, b_3, m_2 = Polygon(O, C, B, M)
n = 0 (slider from 0 to 12, step 1)
多邊形4, j_2, g_2, f_2, p_2 = Polygon(J, G, F, P)
多邊形5, p_3, j_3, l_3, n_4 = Polygon(P, J, L, N)
多邊形6, p_4, i_2, h_2, k_2 = Polygon(P, I, H, K)
多邊形7, p_5, k_3, m_3, o_1 = Polygon(P, K, M, O)
多邊形8, p_6, j_4, k_4 = Polygon(J, K, P)
多邊形9, b_4, a_4, c_5 = Polygon(A, C, B)
多邊形10, p_7, j_5, a_5, c_6 = Polygon(P, J, A, C)
多邊形11, p_8, c_7, b_5, k_5 = Polygon(P, C, B, K)
α = Angle(J, P, F)
β = Angle(A, C, B)
γ = Angle(I, P, K)