X的四次+X的三次+3*X的二次-8X-6
热心网友
X的四次+X的三次+3*X的二次-8X-6原式=(x^2-x-1)(x^2+2x+6)=[x-(1+√5)/2][x+(-1+√5)/2](x^2+2x+6)
热心网友
x^4+x^3+3*x^2-8x-6=(x^2+2x+6)(x^2-x-1)=(x+1+√5i)(x+1-√5i)(x-1/2+√5/2)(x-1/2-√5/2)x^4+x^3-2*x^2=(x^2+2x)(x^2-x)设x^4+x^3+3*x^2-8x-6=(x^2+2x+a)(x^2-x+b),a+b=5,-a+2b=-8,ab=-6a=6,b=-1