f(x) = 0
2/3*x(x^2-4) = 0
x1= 0
x^2-4= 0
x= +-2
Tangenten:
t1(x) = (x-2)*f '(2) + f(2)
f '(x) = 2x^2-8/3
f '(2)= 8- 8/3 = 24/3 -8/3 = 16/3
f(2)= 0
t(x) = (x-2)*16/3 +0 = 16/3*x- 32/3
t2(x) = (x+2)*f '(-2) + f(-2) = (x+2)*(16/3)+0 = 16/3*x +32/3
m(T1) = m(T2) = 16/3
Gleich Steigung bedeutet, dass die Tangenten parallel sind.