Power and radical functions

9000025801

Level: 
A
Find all intersections of the graph of the following function with \(x\)-axis. \[ f(x) = x^{3} - x^{2} - 2x \]
\(X_{1} = [0;0]\), \(X_{2} = [-1;0]\), \(X_{3} = [2;0]\)
\(X = [0;0]\)
\(X_{1} = [0;0]\), \(X_{2} = [-1;0]\)
\(X_{1} = [0;0]\), \(X_{2} = [1;0]\), \(X_{3} = [-2;0]\)

9000025804

Level: 
B
In the following list identify a true statement on the function \(f\). \[ f(x) = (x + 1)(x + 2)(x - 3) \]
The function \(f\) is positive on \(I_{1} = (-2;-1)\) and \(I_{2} = (3;\infty )\).
The function \(f\) is an increasing function (in its whole domain).
The function is decreasing only on \(I = (-1;3)\).
The function is decreasing on \(I_{1} = (-\infty ;-2)\) and \(I_{2} = (3;\infty )\).