Q1. The limit from the right is -4. (The limit from the left, and the value of f(3) are different, but that doesn't matter for the question asked. Taken together, they mean that the limit as x approaches 3 does not exist. But that is not the question asked.)
Q2. f(x) = 4/x.
f'(x) = -4/x^2, so f'(2) = -4/2^2 = -1.
Q3. Since the denominator is zero at x=7, the only answer choice that makes any sense is the first one:
-∞; x = 7
It also happens to be the right one.
