\(y= \frac{2}{3} x^2 - 12x + 9 |-9 \)
\(y-9= \frac{2}{3} x^2 - 12x |:\frac{2}{3} \)
\(\frac{y-9}{\frac{2}{3}}= x^2 - 18x \) quadratische Ergänzung:
\(\frac{y-9}{\frac{2}{3}}+(\frac{18}{2})^2= x^2 - 18x +(\frac{18}{2})^2\) 2.Binom:
\(\frac{y-9}{\frac{2}{3}}+81=(x-\frac{18}{2})^2|\cdot \frac{2}{3}\)
\(y+45=\frac{2}{3}(x-9)^2 |-45 \)
\(y=\frac{2}{3}(x-9)^2 -45 \)
S\((9|-45)\)
\( \frac{2}{3} x^2 - 12x + 9 =\frac{2}{3}(x-9)^2 -45 \)