三次函數的圖形
Author: 吳亭翰

u = Vector((x(Corner[1]), 0), (x(Corner[3]), 0))
v = Vector((0, y(Corner[1])), (0, y(Corner[3])))
a = 2.9 (slider from -5 to 5, step 0.1)
b = 4.4 (slider from -5 to 5, step 0.1)
c = -4.2 (slider from -5 to 9, step 0.1)
d = -2.1 (slider from -5 to 7, step 0.1)
f(x) = a * x^(3) + b * x^(2) + c * x + d
A = TurningPoint(f)
B, C = Extremum(f)
text1: "當X=" + (LaTeX[x(B)]) + "時f(x)有極值" + (LaTeX[y(B)]) + ""
text2: "當X=" + (LaTeX[x(C)]) + "時f(x)有極值" + (LaTeX[y(C)]) + ""
text3: "反曲點" + (LaTeX[A]) + ""
e = 5 (slider from -5 to 5, step 0.1)
g(x) = e
D, E, F = Intersect(g, f)