Let f be a function such that the limit as h approaches 0 [(f(5+h)-f(5))/h]=4. Which of the following must be true?

Question

I. f(5)=4
II. f'(5)=4
III. f is continuous at x=5
A. I only
B. II only
C. III only
D. I and II only
E. II and III only

Answer 1

the value given is the definition of f'(5).

So, II and III are true, making E the correct choice.