Question

一元四次方程求解X^4-8X^3+32X^2-64=0

Answer 1

x^4-8x^3+16x^2+16x^2-64=0

(x^2-4)^2+16(x^2-4)=0

令y=x^2-4

则y^2+16y=0

y=0或y=-16

当y=-16时,x无解

当y=0时,x=±2