Question

What are the solutions of the equation x4 + 3x2 + 2 = 0? Use u substitution to solve.

Answer 1

let x^2=t
t^2+3t+2=0
t^2+2t+t+2=0
t(t+2)+(t+2)=0
(t+2)(t+1)=0
t=-2,-1
x^2=-2
x=i*2^(1/2)
x=i

Answer 2

@sexy12