Analyse the general rational-power family
The point data use the parent coordinate u=n(x-h), so no decimal approximation is needed
The reduced exponent is \(\frac{7}{3}\)
\[f(x)=-\left(x+1\right)^{\frac{7}{3}}\]
For the exact key points, use \(u=n(x-h)=r^3\) with parent offsets \(-1\) and \(2\)