Question 1056812
.
{{{graph( 330, 330, -50.5, 50.5, -50.5, 10.5,
          X^3-x^2-x-2
)}}}


Plot y = {{{x^3-x^2-x-2}}}



Probably, I could prove this inequality,
but since there is NO question in your post, 
I will not do it.