Find the limit of the following log terms 
I thouht about it alot but could not able to getany idea . 
Can anybody provide me a hint

Hint:
$$\lim_{x \to 0} \frac{f(3+x) - f(3-x)}{x} = \lim_{x \to 0} \frac{f(3+x) - f(3)}{x} + \lim_{x \to 0} \frac{f(3-x) - f(3)}{-x} = f'(3) + f'(3)$$
