Read and construct a gradient function from a function graph
The following exact data describe the function on the displayed horizontal scale
\[f(x)=-\left(x+3\right)\left(x-1\right)^2\]
The x-intercepts are \(x=-3,\quad 1\)
The relevant stationary or corner x-values are \(x=-\frac{5}{3},\quad 1\), with points \((-\frac{5}{3},-\frac{256}{27}),\quad (1,0)\)
From left to right, the function has negative slope on x < -5/3; positive slope on -5/3 < x < 1; negative slope on 1 < x