Odpowiedź:
a)
f(x) = (2x² - 8)/(x - 4)
założenie"
x - 4 ≠ 0
x ≠ 4
Df: x ∈ R \ {4}
f(- 1) = [2 * (- 1)²- 8]/(- 1 - 4) = (2 * 1 - 8)/( - 5) = (2 - 8)/(- 5)= -6/(-5)= 6/5=
= 1 1/5 = 1,2
f(0) = [2 * 0² - 8)/(0 - 4) = - 8/(- 4) = 8/4 = 2
f(1) = (2 * 1² - 8)/(1 - 4) = (2 - 8)/(- 3)= - 6/(- 3)= 6/3 = 2
b)
f(x) = (x² + 4)/(x² - 4)
założenie:
x² - 4 ≠ 0
(x - 2)(x + 2) ≠ 0
x - 2 ≠ 0 ∧ x+ 2 ≠ 0
x ≠ 2 ∧ x ≠ - 2
Df: x ∈ R \ {- 2 , 2 }
f(- 1) = [(- 1)²+ 4]/[(- 1)² - 4] = ( 1 + 4)/(1 - 4) = 5/(- 3) = - 5/3 = - 1 2/3
f(0) = (0²+ 4)/(0² - 4) = 4/(- 4) = - 4/4 = - 1
f(1) = (1² + 4)/(1² - 4) = (1 + 4)/(1 - 4) = 5/(- 3) = - 5/3 = - 1 2/3
