@coldwin
(x+1)^4 =2(x^4 +1)
x^4 +4x^3 +6x^2 +4x^2 +1 =2x^4 +2
<=> x^4 -4x^3 +6x^2 -4x^2 +1 =12x^2
<=> (x-1)^4 =12x^2
<=> (x-1)^2 = 2can(3)x
<=> x^2 -2(1+ can3 )x +1 =0 $`
delta (x) = =3+2can(3)
\(x=1+\sqrt{3}\pm\sqrt{3+2\sqrt{3}}\)
(x+1)^4 =2(x^4 +1)
x^4 +4x^3 +6x^2 +4x^2 +1 =2x^4 +2
<=> x^4 -4x^3 +6x^2 -4x^2 +1 =12x^2
<=> (x-1)^4 =12x^2
<=> (x-1)^2 = 2can(3)x
<=> x^2 -2(1+ can3 )x +1 =0
delta (x) = =3+2can(3)
x = 1 + √3 ± √3 + 2√3