拋物線的標準式(1)
Author: 藍邦偉  老師
Date: 8 12 月 2012

$V$

h=

$ V( $

,

k

)

c=

$ c= $

$ 拋物線的標準式(1) $

$ V $

$ F $

$ A $

h = 0 (slider from -5 to 5, step 1)
k = 0 (slider from -5 to 5, step 1)
c = 1 (slider from -5 to 5, step 1)
f: (y - k)^(2) = 4 * c * (x - h)
V: (h, k)
F: (h + c, k)
L: x = h - c
l: y = k
A = Intersect(L, l)
a: x = h + c
l_1: x = h + c
B, C = Intersect(f, l_1)
b = Segment(B, C)
d = Line(B, l)
e = Line(C, l)
D = Intersect(L, d)
E = Intersect(L, e)
g = Segment(D, B)
i = Segment(E, C)
A_1: (x(Corner[1]), 0)
A_2: (x(Corner[2]), 0)
A_3: (0, y(Corner[2]))
A_4: (0, y(Corner[4]))
u = Vector(A_1, A_2)
v = Vector(A_3, A_4)
Step = 0 (slider from 0 to 6, step 1)
T_1 = Corner(1)
T_4 = Corner(4)
T_2: (7.2 * Corner[1] + 2.8 * Corner[2]) / 10
T_3: (7.2 * Corner[4] + 2.8 * Corner[3]) / 10
j = Segment(T_2, T_3)
inputBox1 = Textfield(h)
inputBox2 = Textfield(k)
inputBox3 = Textfield(c)
text6: "頂點V(" + h + "," + k + ")"
poly1, t_1, t_2, t_3, t_4 = Polygon(T_1, T_2, T_3, T_4)
text7: "焦點F(" + (h + c) + "," + k + ")"
text8: "準線L:x=" + (h - c)
text9: "對稱軸l:y=" + k
G = (-5.84, 4.36)
t_f: "$ \Gamma：\;" + (LaTeX[If[k ≟ 0, "", "("]]) + " y" + (LaTeX[If[k > 0, "-" * abs(k), If[k ≟ 0, "", "+" * abs(k)]]]) + "" + (LaTeX[If[k ≟ 0, "^2", ")^2"]]) + "=" + (LaTeX[4 * c]) + "" + (LaTeX[If[h ≟ 0, "", "("]]) + "x" + (LaTeX[If[h > 0, "-" * abs(h), If[h < 0, "+" * abs(h), ""]]]) + "" + (LaTeX[If[h ≟ 0, "", ")"]]) + "$"
n = 0
text10: "正焦弦長4|c|=" + (LaTeX[4 * abs(c)]) + ""