Question 976542
You might have really {{{P(x)=x^4+8x^2}}}.


{{{x^2(x^2+8)}}}


{{{x^2=-2*2*2}}}
{{{x=0+- 2i*sqrt(2)}}}


Complete factorization is {{{P(x)=x^2(x-2i*sqrt(2))(x+2i*sqrt(2))}}}.