Which of the following best describes the discontinuity of the function
f(x)=x−3x2−9
at x=3?
a) No discontinuity; the function is continuous at x=3 since the factor (x−3) cancels.
b) A removable discontinuity because x→3limf(x) exists while f(3) is undefined.
c) A jump discontinuity because the one-sided limits at x=3 are not equal.
d) An infinite discontinuity because f(x) grows without bound as x approaches 3.