TeX Quellcode:

\begin{array}{rcl} f(x) &=& 4x^2 -4x+3 \cr\cr &=& 4 \left(x^2- 1x+ \dfrac{3}{4} \right) \cr\cr &=& 4 \left(x^2 -1x+ \dfrac14 +\dfrac12 \right) \cr\cr &=& 4 \left(x^2 - 2 \cdot \dfrac12 x + \left(\dfrac12 \right)^2 + \dfrac12 \right) \cr\cr &=& 4 \left(\left(x- \dfrac12 \right)^2 +\dfrac{1}{2}\right) \cr\cr &=& 4 \left(x- \dfrac12 \right)^2 +2 \end{array}