Mark M. answered 07/24/18
Tutor
4.9
(954)
Retired math prof. Calc 1, 2 and AP Calculus tutoring experience.
f(x) = (x4-2x3-3x2) / (x4-5x3+6x2)
f is continuous for all x except where the denominator is zero.
x4 - 5x3 + 6x2 = x2(x2 - 5x + 6) = 0
= x2(x-3)(x-2) = 0
x = 0, 3, 2
f is discontinuous at x = 0, 2, 3
f is continuous for all other values of x.