$\left[\left[\mathrm{-5}\,5\right]\,\left[0\,2\right]\,\left[4\,0\right]\right]$

$\left[\left[-5\,5\right]\,\left[0\,2\right]\,\left[4\,0\right]\right]$

$s:=\mathrm{CurveFitting}\left[\mathrm{Spline}\right]\left(\,x\right)$

$s:=\&lcub;\begin{array}{cc}2-\frac{49}{90}x\&plus;\frac{1}{60}{x}^2\&plus;\frac{1}{900}{x}^3& x<0\\ 2-\frac{49}{90}x\&plus;\frac{1}{60}{x}^2-\frac{1}{720}{x}^3& \mathrm{otherwise}\end{array}$