Question 1040850
{{{F(x)= x^3 -x^2 -x -8}}} and F(u) = -8

==> {{{F(u)= u^3 -u^2 -u -8 = -8}}}

==> {{{ u^3 -u^2 -u = 0}}}  ==>  {{{u(u^2-u-1) = 0}}}

==> the roots are u = 0,  {{{u = (1 +- sqrt(5 ))/2 }}}.

==> there are three real values for u.