get into ax²+bx+c=0 form
subsitute u=x⁴
x⁸-3x⁴+2=0
(x⁴)²-3(x⁴)+2=0
u²-3u+2=0
factor
(u-2)(u-1)=0
set to zero
u-2=0
u=2
u-1=0
u=1
wait, u=x⁴
2=x⁴
[tex]\sqrt[4]{2}=x[/tex]
1=x⁴
+/-1=x
the subsitution is u=x⁴
and the possible values for x are -1, [tex]\sqrt[4]{2}=x[/tex], and 1
