TeX Quellcode:

\begin{array}{rcl} f(x) &=& \dfrac{1}{4}x^2-6x+32 \cr \cr &=& \dfrac{1}{4}(x^2-24x+128) \cr \cr &=& \dfrac{1}{4}(x^2-24x+144-16) \cr \cr &=& \dfrac{1}{4}(x^2-2 \cdot 12x+12^2-16) \cr \cr &=& \dfrac{1}{4}((x-12)^2 -16) \cr \cr &=& \dfrac{1}{4}(x-12)^2-4 \end{array}