Question 256893
{{{ graph( 300,300, -10, 10, -10, 10, 1+1*(x+3), 1-1*(x+3) ,1+0*(x+3) ,1+2*(x+3) ,1-2*(x+3)  ) }}} 
Here's the graph for m=-2,-1,0,1,2.
You can draw your conclusions from the graph. 
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The simplest cubic polynomial is
{{{f(x)=A(x+1)(x-0)(x-2)}}}
{{{f(1)=A(2)(1)(-1)=6}}}
{{{-2A=6}}}
{{{A=-3}}}
{{{f(x)=-3x(x+1)(x-2)}}}