f(x)=\( \frac{x^{2}}{2} \)
f(x+h)=\( \frac{(x+h)^{2}}{2} \) = \( \frac{x^{2}+2hx+h^{2}}{2} \)
\( \frac{f(x+h)-f(x)}{h} \) = \( \frac{x^{2}+2hx+h^{2}}{2h} \) - \( \frac{x^{2}}{2h} \)
=\( \frac{2hx+h^{2}}{2h} \)=x + \( \frac{h}{2} \)
Für h→0 ist das x.