Question

Graph the function f(x) = x3 – 3x – 2. Based on the graph, which value for x is a double root of this function? a.–2 b.–1 c.1 d.2

Answer 1

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