\(\lim\limits_{x\to 0} \frac{f(2 + h)- f(2 -h)}{h}\)
\(= \lim\limits_{x\to 0} \frac{f(2 +h)- f(2 + f(2) - f(2 -h))}{h}\)
\(= \lim\limits_{x\to 0} \frac{f(2 +h) - f(2)}{h} + \lim\limits_{h\to 0} \frac{f(2 -h) - f(2)}{-h}\)
\(= f'(2) + f'(2)\)
\(= 2f'(2)\).