Question

解一道一元二次方程,急,(x^2+1)^2-x^2=3

Answer 1

(x^2+1)^2-x^2=3

x^4+2x^2+1-x^2=3

x^4+x^2-2=0

(x^2-1)(x^2+2)=0

x^2=1或x^2=-2 （舍）

∴x^2=1

x=±1