a

L

L + ε

L-ε

a-δ

a+δ

f(x) = 1 / x
a_1 = 1 (slider from -5 to 5, step 0.1)
L_1: (0, f(a_1))
B: (a_1, f(a_1))
A: (a_1, 0)
delta = 0.05 (slider from 0 to 1, step 0.01)
aMinusDelta: a_1 - delta
aPlussDelta_1: a_1 + delta
AMinusDelta: (aMinusDelta, 0)
APlussDelta: (aPlussDelta_1, 0)
F: (aMinusDelta, f(aMinusDelta))
K: (aPlussDelta_1, f(aPlussDelta_1))
b = Segment(AMinusDelta, F)
c = Segment(A, B)
d = Segment(APlussDelta, K)
H: (0, f(a_1))
e = Segment(H, B)
I: (0, f(aMinusDelta))
g = Segment(I, F)
L: (0, f(aPlussDelta_1))
h = Segment(L, K)
C = (1.2, 1.2)
G = (2.813827160493839, 1.2)
epsilon = 0.08 (slider from 0 to 1, step 0.01)
LPlussEpsilon: (0, f(a_1) + epsilon)
LMinusEpsilon: (0, f(a_1) - epsilon)