Question

x4-2x3-6x2+6x+9=0求x的值,x的4次方-2x的3...

Answer 1

x^4-2x^3-6x^2+6x+9=0

x^4-2x^3-3x^2-3x^2+6x+9=0

x^2(x^2-2x-3)-3(x^2-2x-3)=0

(x^2-2x-3)(x^2-3)=0

(x-3)(x+1)(x+√3)(x-√3)=0

x1=3

x2=-1

x3=-根号3

x4=根号3