证明:
f(x)=6x^4-x^3-6x^2-x-12
=6(x^4-x^2-2)-(x^3+x)
=6(x^2-2)(x^2+1)-(x^2+1)x
=(x^2+1)(6x^2-12-x)
=(x^2+1)(2x-3)(3x+4)
两个问题得证