Webgrafieken
Author: Harm Houwing

Gegeven is de recursieve formule u_n = -u_{n-1} + b 
met beginterm u_0 = 1.
Voor welke waarde van b  geldt dat alle termen 
met een oneven rangnummer n gelijk zijn aan 7?
Controleer je antwoord op de GR. 

b = 6.5 (slider from 0.1 to 8, step 0.1)
u_0 = Point(xAxis)
a = -0.7000000000000002 (slider from -5 to 5, step 0.1)
f(x) = a x + b
P_1: (x(u_0), f(x(u_0)))
Q_1: (y(P_1), y(P_1))
u_1: (x(Q_1), 0)
P_2: (x(u_1), f(x(u_1)))
Q_2: (y(P_2), y(P_2))
u_2: (x(Q_2), 0)
P_3: (x(u_2), f(x(u_2)))
Q_3: (y(P_3), y(P_3))
u_3: (x(Q_3), 0)
P_4: (x(u_3), f(x(u_3)))
Q_4: (y(P_4), y(P_4))
u_4: (x(Q_4), 0)
P_5: (x(u_4), f(x(u_4)))
Q_5: (y(P_5), y(P_5))
u_5: (x(Q_5), 0)
d = Segment(u_0, P_1)
e = Segment(P_1, Q_1)
g = Segment(Q_1, u_1)
h = Segment(Q_1, P_2)
i = Segment(P_2, Q_2)
j = Segment(u_2, Q_2)
k = Segment(P_3, Q_2)
l = Segment(P_3, Q_3)
m = Segment(Q_3, u_3)
n = Segment(Q_4, u_4)
p = Segment(Q_3, P_4)
q = Segment(P_4, Q_4)
r = Segment(Q_4, P_5)
s = Segment(Q_5, u_5)
t = Segment(P_5, Q_5)
text1: "u_0 = " + (x(u_0)) + "
u_1 = " + (x(u_1)) + "
u_2 = " + (x(u_2)) + "
u_3 = " + (x(u_3)) + "
u_4 = " + (x(u_4)) + "
u_5 = " + (x(u_5))
text3: "f(x) = " + f