The function F is continuous on the interval -1<x<3 and is not continuous on the interval -1<= x <= 3. Which of the following could NOT be an expression for f(x)?

Question

The function F is continuous on the interval -1<x<3 and is not continuous on the interval -1≤ x ≤ 3. Which of the following could NOT be an expression for f(x)?

1) x+1/ x-3

2) x-3/ x+1

3) (x+1) (x-3)

4) 1/ (x+1)(x-3)

Apologies for not being able to put it in fraction form

Answer 1

Choice 3) cannot be an expression for f(x) because it is continuous everywhere.

In contrast, all the other choices make the function undefined at one or both of the interval's ends,

consistent with the description of f(x)