To solve the problem shown above you must apply the following proccedure:
1. You have the following function given in the problem:
f(x)=x3–3x–2
2. When you give values to the x and plot each point obtained, you obtain the graph shown in the figure attached.
3. Based on the graph and analizing the alternate form:
f(x)=(x-2)(x+1)²
As you can see, there is two roots x=-1, then, you can conclude that the correct answer is the option b, which is:
b) -1